Papers by Keyword: Humidity

Abstract: Reducing the toxicity of plywood encourages the use of dry powder mixtures of polyester resin, as its dissolution in organic matter reduces environmental safety. The paper presents the results of studies of free surface energy and its components (polar and dispersed) for plywood, which is made on the basis of polyester resin. The sequences of polarity change and their ratio to the main component of wood after the formation of plywood board at high temperature, which are consistent with the structural and functional features of thermally modified wood. The resulting plywood is characterized by a reduced property of water absorption, because the free surface energy is reduced by 2.3 times and the polarity by 2 times, which is due to the thermal modification of the veneer. Thus, when applying a comprehensive approach to the study of wettability, polarity, interfacial tension, you can choose stable technologies for new wood products and expand its scope.

Abstract: Premature babies born before 38 weeks have a high risk of dying, requiring urgent care. Premature babies receiving intensive care in incubators need certain temperature, humidity, and a quiet room. In addition, the baby should also be ensured that his body temperature remains normal during the treatment period. Based on the condition of these vulnerable babies, it is very necessary to have a temperature monitoring system in the incubator. Therefore, the purpose of this research is to develop a baby incubator monitoring system that still uses the manual method to make it faster, easier, and more practical. This module is a tool that works independently and is not part of the baby incubator. Therefore, any brand of the incubator can be monitored using this module. The system in this module is wireless and uses a Wi-Fi network for data transmission. By using several ESP32 modules assembled into a central system, the data obtained from monitoring each sensor will be processed by the ESP32 which functions as a client, and collected at the central point of the ESP32 which functions as a server using the internal wifi network of the ESP32 itself as data transmission. The data from the server will subsequently be shown on the TFT Nextion display. Based on the overall measurement results using 2 baby incubators, the highest error values ​​were 1.387% for the incubator temperature parameter, 3.911% for the skin temperature parameter, 10.5% for the humidity parameter, and 25.692% for the noise parameter. The results showed that the module that was made still contained errors in each measurement. The results of this study will assist nurses in more simply and swiftly monitoring premature newborns.

Abstract: Non-observance of the heat and humidity regime in buildings can lead to significant problems such as the formation of condensation on the internal surfaces of the enclosing structures, which not only destroys the construction of the building but also leads to the formation of mould, fungi that are dangerous for human life and health. In addition, the use of construction or thermal insulation materials in a humid environment increases the energy consumption as a result of which the building's energy efficiency is reduced. In this paper considered the impact of the heat and humidity regime on the construction and thermal insulation materials, and also presents a developed new structure of an air dryer dehumidifier. The results of the study showed that an increase in the moisture content of the construction material by 10%, the thermal conductivity of the material increases from 6% to 60%, which will significantly increase the heating and cooling demand of the building. The developed new structure of the air dehumidifier reduces the humidity of the air, without using additional equipment, or substance such as refrigerant or absorbent. The proposed device significantly reduces capital and operating costs.

Abstract: The implementation of glass in various industries may cause some problems due to its brittleness characteristic. Its usage in the transportation sector has led to death and serious injuries to drivers and passengers in vehicles. It shows that the manufacturing process of the materials used requires an improvement in terms of brittleness to provide better protection to the consumer. Therefore, rubber toughened PMMA (RT-PMMA) was introduced as the rubber has the ability to increase the ductility of PMMA. PMMA and two different grades of RT-PMMA namely RT-PMMA65 and RT-PMMA100 were taken into consideration to investigate the effect of different rubber contents on the ductility of PMMA. Other than strain rate and temperature, humidity is also one of the factors that affect the ductile properties of PMMA. In this study, tensile tests at different humidity levels (11% and 98%) will be carried out by immersing the specimens in two different solutions which are lithium chloride (LiCl) and potassium sulfate (K₂SO₄) beforehand. The output from the experimental works proved that the tensile properties of RT-PMMA are affected by the presence of humidity for all three grades of PMMA under consideration. It is also proved that RT-PMMA100 is more ductile compared to RT-PMMA65 on the tensile test.

Abstract: The article presents the results of studies of the surfaces of parts processed by the contactless method of laser polishing. The results of technological surface treatment using a laser technological complex based on an ytterbium fibre laser with a power of 5 kW are presented. The results of studies of the surface roughness of the samples after laser treatment, including the non-uniform character due to the redistribution of the liquid metal melt over the surface, are shown. Requirements for metrological support of additive technology have been developed using the example of the process of laser remelting in order to improve quality and further automation.

Abstract: Energy saving in buildings is largely determined by the energy efficiency of the external building envelopes. The latter, as a rule, are the multilayer and incorporate structural and heat-insulating layers. The presence of individual hygroscopic salts and their mixtures in building materials changes their physical and chemical properties. Due to the increase in the sorption properties of building materials and changes in the inter-pore substance composition, humidity increases and the heat-protective properties decrease. This paper presents the results of the experimental and theoretical studies on the salts’ effect assessment on the change in moisture content and thermal conductivity of building materials due to the salt solutions and crystals’ presence in the pore space. To study the saline building materials’ thermal conductivity, the mathematical modeling methods using the theory of flow and bringing the materials’ structure to a unit cell are used. It is shown that the change in thermal conductivity occurs due to the crystalline salt precipitation from the solutions in the material’s pores, to the changes in their initial chemical properties, to the changes in the properties of the vapor-air mixture above the salt solutions due to diffusion. The results obtained make it possible to establish the hygroscopic salts’ influence significance in solid and liquid phases on the building materials’ thermal conductivity. A scheme for determining the thermal conductivity of building materials is proposed, taking into account salt effects, including the determination of: the components’ volume concentrations; sequentially the thermal conductivity of the material’s shell; salt crystals, a solid phase consisting of the material’s shell and crystalline salt, a binary and multicomponent saline solution, the pore space and the pore substance inside. The general formula for determining the thermal conductivity of a saline building material is given.

Abstract: Polypropylene bags are widely used in many industries especially in agriculture and food industry. However, industries especially in food or fertilizer industries, need to use the polypropylene bags that can withstand a high level of humidity. To overcome this problem, a two-layers bag is required. This two-layers bag consists of outer layer woven bag and inner layer polypropylene bag. Currently they are produced by using conventional method where they are assembled manually by the workers. This manual method causes longer production time process, a high number of workers, and higher cost for mass production. To enhance the operation performance, automated polypropylene bags assembly system is proposed. By using an automated system, it can improve quality and consistency of processes, and reduced direct human labor costs and expenses where the worker is unneeded for assembling the polypropylene bag. To overcome this problem, this project is dedicated to design and develop a new Automated Polypropylene Bag Assembly Machine (APBAM) to operate the process automatically. This machine will execute three main processes - Grasping, Handling and Feeding. This paper will focus on the design of pneumatic actuator for grasping polypropylene bags in upward and downward motion. The design will be calibrated, analyzed and evaluated. The design of automated polypropylene bags assembly system will help to solve some of the problems that have been identified.

Abstract: A negative resist composition composed of an acrylic-copolymer-binder resin, a crosslinker, photoinitiators, some agents and solvents has been UV-cured and developed for OverCoat (OC)-Bridge of One Glass Solution (OGS) touch panel (TP) sensor, wherein acrylic-copolymer-binder resin as a key element consisting of N-Phenylmaleimide (N-Pm), Methacrylic acid (MA), Styrene (St) and Isobornyl methacrylate (iBMA) monomers, being designed and synthesized to control the acid value (90-110mgKOH/g), molecular weight (Mw:10,000-20,000) and approximate solubility parameter [10.67-11.05(cal/cm3)1/2]. Here,we demonstrate a OC photoresist applies between two ITO line-films by UV-curing process technology deveoled for OC-Bridge pattern with a kind of acrylic-copolymer-binder resin by ours. Acting as TP sensor, the OC patterns have adequate resistance to solvents, acids and alkalis, good thermal and humid stability, and with excellent transparency and insulation. This OC photoresist, coupled with the acrylic-copolymer-binder resins, provides an unprecedented approach to realize supporting high temperature and humidity OC-Bridge.

Abstract: The paper shows a type of experimental installation intended for the drying of cereals with a dual source of energy, electrothermal and solar, resulting in very close or even identical results of the humidity and drying temperature of the used samples.

Abstract: This article reflects the results of a set of studies on obtaining a face ceramic brick of soft molding with the search for raw materials and the development of an optimal production technology. It proposed and formulated the basic requirements for opoka-like rocks for the production of various types of wall ceramic products. They include recommendations on the chemical composition and such physical, mechanical and technological properties as density in the piece, natural humidity, porosity, mineral composition, compressive strength of the baked samples, fire shrinkage, water absorption, average density, etc. We proposed the so-called "soft molding" as a production technology. It is based on the principle of filling individual forms with a ceramic mass that has a certain plasticity and binding capacity. The appearance of such a brick is characterized by the absence of smooth edges and sides and rounded corners. The sand used for spilling forms produces a special effect of velvety and old-looking brick. The conclusions based on the results of laboratory and technological research as well as factory tests revealed the great promise for using opoka-like rocks as a raw material for the production of face ceramic bricks of soft molding.