Study on the hygroscopicity of PET foam sandwich structure

Polyethylene terephthalate (PET) foam sandwich structure is widely used in the fields of construction, aerospace and shipbuilding. We have conducted research on its hygroscopic phenomenon. Take different sizes of GFRP panels, PET foam and PET foam sandwich structure for moisture absorption tests, analyze the data on the basis of the classic Fick’s law of diffusion to obtain the moisture absorption curves of each sample. And get the diffusion coefficient of the specimen. Then, we use the multi-physics software COMSOL to model and analyze the moisture absorption properties of the specified samples. The moisture absorption curve obtained by theoretical calculation was compared with the experimental moisture absorption curve, and the results showed that the two Good agreement. Tests have proved that the moisture absorption performance of PET foam is much greater than that of GFRP panel material, and the relative moisture absorption is related to the specific surface area of the sample. In the PET foam sandwich structure, the GFRP panel can effectively inhibit the hygroscopicity of the PET foam and has an excellent protective effect on the PET foam.

PHOTO-CATALYSIS PROCESSES IN NON-REGULAR MEDIA

Technologies that cause the least harm to nature from global warming standpoint are becoming called-for. In this regard, photo-catalysis which uses the solar energy for chemical transformations of substances is of great interest for studying possible mechanisms of such processes. At the same time, the use of photo-catalysis significantly expands capabilities of the synthesis of new organic and inorganic materials. Charge phototransfer is always at the heart of photochemical transformations. Such processes can be considered from the point of view of quantum mechanics, and the probability of various mechanisms of the passing processes can be calculated using the apparatus of Green's functions. Analytical expressions for kinetic parameters of the charge transfer process between polyatomic particles in non-regular condensed medium and expressions for the extinction coefficient for appropriate processes of charge photo-transfer are obtained. Based on the analysis of obtained analytical expressions of dark and optical charge transfer processes, correlations between kinetic parameters of these processes are obtained. A methodology for determining kinetic parameters of the charge photo-transfer process on the basis of the shape of light absorption curve by means of the system functioning as the frequency of absorbed photons in various systems is presented. In this respect the general methodology has been applied to various specific processes. A methodology for determining the kinetic parameters of the charge phototransfer process from the shape of the light absorption curve by the system as a function of the frequency of absorbed photons in various systems is presented. The general methodology presented has been applied to various specific processes.

Absorption of CO2 in DMAEE-DGA-DBU Aqueous Solution

39 sets of solutions were compounded from 2-[2-(Dimethylamino)ethoxy]ethanol (DMAEE), 2-(2-Aminoethoxy)ethanol (DGA) and 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU). There solutions were tested relevant to the stirred reactor, at 303K~323K, 0.1MPa, to establish their absorption performance. An equation was utilized to model the absorption curve and the simulation results agreed well the experiments. The relevance of temperature and composition of solution with absorbed performance were revealed on the basis of comparison and analysis.

Biometric characterization, water absorption curve and vigor on araçá-boi seeds

Araçà-boi is a fruit, which awakes great interest for presenting pulp of quality. Their seeds are recalcitrant and present a relatively short period of viability. The water absorption by seeds is a mechanism of growth resuming of the embryo with a subsequent of the tegument breakage by the radical. The seed electric conductivity is a vigor testing is directly related to the membrane permeability. Study of the curve of water absorption by the araçá-boi seeds will contribute to characterize their germination process. In this context, studies concerned with seeds were conducted, which characterized the mass, biometrics, water content, electric conductivity and water imbibition by seeds. It was found that the population of plants established in Manaus-AM produces small, medium and large seeds and which present 70.2, 68.2 and 47.5% of moisture. The greatest water increase takes place in the first hour of absorption, regardless of the size of seeds and water absorption velocity is not influenced by their size. The imbibition curves characterized in the 144-hour period, independent of the size of seeds, show changes of two physiological phases. Both the large and medium seeds present smaller conductivity values, obtaining smaller percentages of germination for possessing increased vigor indices.

Biometric description of fruits and seeds, germination and imbibition pattern of desert rose [Adenium obesum (Forssk.), Roem. & Schult.]

This study has aimed to carry out the description of fruits and seeds and germination process of desert rose, from two years of observations. The fruits and seeds were characterized based on length, diameter and number of seeds per fruit. The seeds internal structure and germinating process were also described. Germination test was performed at 25 and 30 °C temperatures, determining the germination percentage and germination speed index. Seeds harvested in 2013 were stored for 12 months and submitted to a new germination test. Parallel to these tests, the seeds imbibition curve was determined in substrates over and between sheets of paper at 15, 20, 25 and 30 °C temperatures. The fruits and seeds had similar lengths and diameters in both years of observations. The seeds can be stored for up to 12 months without loss in viability and temperatures of 25 and 30 °C are suitable for performing the germination test of this species. The water absorption curve of desert rose seeds follows a triphasic pattern of soaking.

Perbaikan Proses Pembuatan Gula Merah Aren di Pabrik Gula Aren Masarang Tomohon

Pabrik gula aren Masarang Tomohon saat ini memiliki masalah rendahnya efisiensi produksi akibat pembentukan bongkahan gula selama tahap akhir pemprosesan gula. Tujuan penelitian ini adalah untuk meningkatkan efisiensi proses produksi gula di pabrik dengan penekanan pada sorpsi air oleh gula dan pada penghancuran bongkahan gula selama produksi serbuk gula aren (gula semut). Umur simpan gula merah aren diestimasi dengan kurva isoterm absorpsi menggunakan rumus Labuza. Penghancuran gula dilakukan mula-mula melalui penentuan jenis gilingan, diikuti dengan membuat desain gilingan dan membangun konstruksi gilingan. Perhitungan umur simpan gula menghasilkan angka 6,4 tahun umur simpan. Konstruksi gilingan gula dibuat didasarkan pada gilingan martil (hammer mill) dengan kapasitas untuk mengurangi sisa produk hingga 1,28 persen.The Masarang Palm Sugar Factory in Tomohon is currently facing to the problems of the low efficiency production due to the crumble formation during the last step of sugar processing and the question of the shelf life of the product. Therefore the goal of this research is to improve the palm sugar processing at the factory by focusing to the understanding the water sorption by the sugar and to break down the sugar crumbles during the brown sugar powder production. The shelf life of the brown palm sugar was estimated by the isotherm absorption curve followed by application of Labuza formula. The sugar milling was processed by firstly determined the milling type, followed by designing the mill and then constructed it. The calculation of shelf life of the sugar product was found as 6.4 years. The sugar milling was constructed based on the hammer mill with the capacity to reduce the crumbles as low as 1.28 percent.