Study of the Structure and Oxygen Permeability of Cellulose Packaging Films from NMMO-Solutions

2011 ◽  
Vol 380 ◽  
pp. 148-151
Author(s):  
Pei Fang Cheng ◽  
Jian Qing Wang ◽  
Wen Ming Ren
Keyword(s):  
Fruits And Vegetables ◽  
Oxygen Permeability ◽  
Processing Parameters ◽  
High Oxygen ◽  
Raw Material ◽  
Coagulation Bath ◽  
Process Conditions ◽  
Packaging Films ◽  
Cellulose Films ◽  
And Performance

This paper is concerned with the preparation of cellulose packaging films with high oxygen permeability. The films were prepared from cotton pulp and wood pulp by the cast-wiped method using N-methymorpholine-N-oxide (NMMO) as a solvent. The effects of processing parameters on the structure and performance of cellulose films were also studied. The results show that for optimum processing of the films cotton pulp was the preferred raw material, the optimum pulp concentration in the casting solution was 5%, and the optimum temperature for the coagulation bath was 40°C. Using the above process conditions resulted in packaging films with high oxygen permeability making them suitable for use in packaging fruits and vegetables.

scholarly journals Morphological and Rheological Guided Design for the Microencapsulation Process of Lactobacillus paracasei CBA L74 in Calcium Alginate Microspheres

2021 ◽  
Vol 9 ◽  
Author(s):  
Concetta Di Natale ◽  
Elena Lagreca ◽  
Valeria Panzetta ◽  
Marianna Gallo ◽  
Francesca Passannanti ◽  
...  
Keyword(s):  
Production Process ◽  
Calcium Alginate ◽  
Bacterial Species ◽  
Processing Parameters ◽  
Lactobacillus Paracasei ◽  
Process Conditions ◽  
New Era ◽  
Encapsulation Process ◽  
Metabolic Activities ◽  
And Performance

The intestinal microbiota is a real ecosystem composed of several bacterial species and a very huge amount of strains that through their metabolic activities play a crucial role in the development and performance of the immune system and other functions. Microbiota modulation by probiotics establishes a new era into the pharmaceutical and healthcare market. Probiotics play, in fact, an important role in helping and sustaining human health, but in order to produce benefits, their viability must be preserved throughout the production process up to consumption, and in addition, their bioactivity required to be safeguarded while passing through the gastrointestinal tract. In this frame, encouraging results come from encapsulation strategies that have proven to be very promising in protecting bacteria and their viability. However, specific effort has to be dedicated to the design optimization of the encapsulation process and, in particular, to the processing parameters that affect capsules microstructure. Herein, focusing on calcium alginate microspheres, after a preliminary selection of their processing conditions based on size distribution, we implemented a micro-rheological analysis, by using the multiple-particle tracking technique, to correlate the inner microstructure to the selected process conditions and to the viability of the Lactobacillus paracasei CBA L74. It was assessed that the explored levels of cross-linking, although changing the microorganism constriction, did not affect its viability. The obtained results confirm how this technology is a promising and a valid strategy to protect the microorganism viability and ensure its stability during the production process.

scholarly journals Utilization of Cumbeba (Tacinga inamoena) Residue: Drying Kinetics and Effect of Process Conditions on Antioxidant Bioactive Compounds

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 788
Author(s):  
João Paulo de Lima Ferreira ◽  
Alexandre José de Melo Queiroz ◽  
Rossana Maria Feitosa de Figueirêdo ◽  
Wilton Pereira da Silva ◽  
Josivanda Palmeira Gomes ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Bioactive Compounds ◽  
Fixed Bed ◽  
Drying Kinetics ◽  
Raw Material ◽  
Process Conditions ◽  
Temperature Range ◽  
Water Diffusivity ◽  
Pharmaceutical Industries ◽  
Effective Water

The residue generated from the processing of Tacinga inamoena (cumbeba) fruit pulp represents a large amount of material that is discarded without proper application. Despite that, it is a raw material that is source of ascorbic acid, carotenoids and phenolic compounds, which are valued in nutraceutical diets for allegedly combating free radicals generated in metabolism. This research paper presents a study focused on the mathematical modeling of drying kinetics and the effect of the process on the level of bioactive of cumbeba residue. The experiments of cumbeba residue drying (untreated or whole residue (WR), crushed residue (CR) and residue in the form of foam (FR)) were carried out in a fixed-bed dryer at four air temperatures (50, 60, 70 and 80 °C). Effective water diffusivity (Deff) was determined by the inverse method and its dependence on temperature was described by an Arrhenius-type equation. It was observed that, regardless of the type of pretreatment, the increase in air temperature resulted in higher rate of water removal. The Midilli model showed better simulation of cumbeba residue drying kinetics than the other models tested within the experimental temperature range studied. Effective water diffusivity (Deff) ranged from 6.4890 to 11.1900 × 10−6 m2/s, 2.9285 to 12.754 × 10−9 m2/s and 1.5393 × 10−8 to 12.4270 × 10−6 m2/s with activation energy of 22.3078, 46.7115 and 58.0736 kJ/mol within the temperature range of 50–80 °C obtained for the whole cumbeba, crushed cumbeba and cumbeba residue in the form of foam, respectively. In relation to bioactive compounds, it was observed that for a fixed temperature the whole residue had higher retention of bioactive compounds, especially phenolic compounds, whereas the crushed residue and the residue in the form of foam had intermediate and lower levels, respectively. This study provides evidence that cumbeba residue in its whole form can be used for the recovery of natural antioxidant bioactive compounds, mainly phenolic compounds, with the possibility of application in the food and pharmaceutical industries.

A New Series of Co-Free Oxides with High Oxygen Permeability

1997 ◽  
Vol 130 (2) ◽  
pp. 316-318 ◽  
Author(s):  
Li Siwen ◽  
Yang Weishen ◽  
Fang Lianqing ◽  
Lin Liwu
Keyword(s):  
Oxygen Permeability ◽  
High Oxygen

scholarly journals Factors Affecting the Metal Recovery Yield during Induction Melting of Aluminium Swarf

2012 ◽  
Vol 730-732 ◽  
pp. 781-786
Author(s):  
Hélder Puga ◽  
Joaquim Barbosa ◽  
Carlos Silva Ribeiro
Keyword(s):  
Processing Parameters ◽  
High Energy ◽  
Metal Recovery ◽  
Raw Material ◽  
Protective Atmosphere ◽  
Induction Melting ◽  
Recovery Rates ◽  
Recovery Yield ◽  
High Efficient ◽  
Machining Operations

Machining operations of cast parts usually generate considerable amounts of waste in the form of chips (usually 3–5% of the casting weight). Traditionally, swarf is sold to scrapers and remelters, but this option is quite expensive because the selling price is roughly 30% of the acquisition price of the commercial 2nd melt raw material. For most aluminium foundries that incorporate machining operations in their products, reusing aluminium chips as raw material for the melting stocks is perhaps the best option as waste management policy in what concerns to economical and technical aspects. Nevertheless, aluminium swarf is a low density product (0.25 kg/dm3) and is usually covered by a thin film of aluminium oxide and machining fluid. Melting such a product without suitable previous preparation leads to very low metal recovery rates, high energy consumption, gases and smoke generation and very low quality of the final product. During the last years, the authors have developed a high efficient and environmentally friend aluminium swarf recycling technique, using direct incorporation in aluminium melts. The influence of processing parameters, namely melt temperature and holding time, melting atmosphere, swarf briquetting pressure and melting charge composition in the metal recovery yield and dross generation was studied and characterized, and the optimal processing parameters were established. The microstructure of the final product obtained in those conditions was evaluated and is also presented. It is shown that the recycling efficiency depends on the swarf conditioning, the melting technique and the melt treatment methodology. Swarf moisture reduction, induction melting under protective atmosphere and a specially developed degassing technique were found the most important factors influencing the recycling process. By using the developed technique, cast ingots with microstructure and sanity similar to commercially available AlSi12Cu1 2nd melt raw material were successfully obtained with minimal dross formation and metal recovery rates around 90%, without using traditional salts and fluxes.

Analysis on vibration characteristics of screw in filling process of dynamic injection molding machine

2016 ◽  
Vol 36 (8) ◽  
pp. 861-866 ◽  
Author(s):  
Quan Wang ◽  
Zhenghuan Wu
Keyword(s):  
Injection Molding ◽  
Processing Parameters ◽  
Axial Vibration ◽  
Filling Process ◽  
Molding Machine ◽  
Lumped Mass ◽  
Injection Molding Machine ◽  
Injection Speed ◽  
And Performance ◽  
Injection Screw

Abstract This paper presents a study of the characteristics of axial vibration of a screw in the filling process for a novel dynamic injection molding machine. By simplifying a generalized model of the injection screw, physical and mathematic models are established to describe the dynamic response of the axial vibration of a screw using the method of lumped-mass. The damping coefficient of the screw is calculated in the dynamic filling process. The amplitude-frequency characteristics are analyzed by the simulation and experimental test of polypropylene. The results show that the amplitude of a dynamic injection molding machine is not only is related to structure parameters of the screw and performance of the material, such as non-Newtonian index, but also depends on the processing parameters, such as vibration intensity and injection speed.

NATURE-BASED SOLUTIONS FOR CLIMATE RESILIENT BUILDINGS AND CITIES

2020 ◽  
Author(s):  
Barbara Widera
Keyword(s):  
Urban Design ◽  
Well Being ◽  
Sustainable Growth ◽  
Environmental Benefits ◽  
Raw Material ◽  
End User ◽  
Material Consumption ◽  
Local Conditions ◽  
Sustainable Urbanization ◽  
And Performance

The paper addresses the topic of nature-based solutions applied in the architectural and urban design. These ideas are analyzed in the context of the opportunities they create for the humanity in terms of the sustainable growth and environmental protection. Nature-based solutions are inherently taken from nature. The first part of the paper presents their tremendous potential to be energy and resource-efficient, and resilient to change. In the second part of the research particular concepts driven from nature (copied form nature or inspired by nature) proposed for the buildings and cities are described and evaluated. The author discusses their functional usefulness, spatial appropriateness, adaptation to local conditions, end-user comfort, environmental benefits and the possibility of duplication. Nature-based solutions applied in urban planning can make cities more climate resilient and contribute to ecosystems restoration. The paper describes how sustainable urbanization can stimulate economic growth, make cities more attractive and enhance well-being of the inhabitants. It is also explained how particular buildings can benefit from the concepts driven from nature e.g. by increasing their energy efficiency and performance in terms of raw material consumption. In purpose to properly response to the climate challenge, humanity has to establish a new kind of partnership with nature. Using nature-based solutions should be considered as an important part of this approach. The concepts presented in this paper show some of the most promising options, such as integration of living systems with built systems and innovative combinations of soft and hard engineering. In conclusion some of the most promising nature-based solutions for climate resilient buildings and cities are indicated

scholarly journals Experimental Design and Performance Analysis in Plasma Arc Surface Hardening

2012 ◽  
pp. 57-75
Author(s):  
Mohd Idris Shah Ismail ◽  
Zahari Taha ◽  
Mohd Hamdi Abdul Shukor
Keyword(s):  
Surface Roughness ◽  
Experimental Design ◽  
Surface Hardening ◽  
Processing Parameters ◽  
Plasma Arc ◽  
Signal To Noise ◽  
Scanning Velocity ◽  
Hardening Process ◽  
Arc Current ◽  
And Performance

In this paper, the experimental design by using the Taguchi method was employed to optimize the processing parameters in the plasma arc surface hardening process. The evaluated processing parameters are arc current, scanning velocity and carbon content of steel. In addition, the significant effects of the relation between processing parameters were also investigated. An orthogonal array, signal-to-noise (S/N) ratio and analysis of variance (ANOVA) were employed to investigate the effects of these processing parameters. Through this study, not only the increasing in hardened depth and improvement in surface roughness, but the parameters that significantly affect on the hardening performance were also identified. Experimental results showed the effectiveness of this approach. Dalam kertas kerja ini, reka bentuk ujikaji menggunakan kaedah Taguchi digunakan untuk mengoptimumkan parameter pemprosesan dalam proses arka plasma pengerasan permukaan. Parameter pemprosesan yang dinilai adalah arus arka, halaju imbasan dan kandungan karbon dalam keluli. Sebagai tambahan, kesan-kesan penting yang lain seperti hubungan di antara parameter pemprosesan juga diselidiki. Tatasusunan ortogon, nisbah signal to noise (S/N) dan analisis varians (ANOVA) digunakan untuk mengkaji kesan parameter pemprosesan ini. Melalui kajian ini, bukan sahaja kedalaman pengerasan bertambah dan kekasaran permukaan lebih baik, malah parameter pemprosesan yang nyata sekali menpengaruhi prestasi pengerasan dikenal pasti. Hasil percubaan mengesahkan keberkesanan pendekatan ini.

scholarly journals Effects of Injection Molding Screw Tips on Polymer Mixing

2018 ◽  
Vol 62 (3) ◽  
pp. 241-246 ◽  
Author(s):  
Dániel Török ◽  
József Gábor Kovács
Keyword(s):  
Injection Molding ◽  
Processing Parameters ◽  
Raw Material ◽  
Molding Machine ◽  
Surface Color ◽  
Melt Temperature ◽  
Injection Molding Machine ◽  
Aesthetic Appearance ◽  
Molded Parts ◽  
Injection Molded

In all fields of industry it is important to produce parts with good quality. Injection molded parts usually have to meet strict requirements technically and aesthetically. The aim of the measurements presented in our paper is to investigate the aesthetic appearance, such as surface color homogeneity, of injection molded parts. It depends on several factors, the raw material, the colorants, the injection molding machine and the processing parameters. In this project we investigated the effects of the injection molding machine on surface color homogeneity. We focused on injection molding screw tips and investigated five screw tips with different geometries. We produced flat specimens colored with a masterbatch and investigated color homogeneity. To evaluate the color homogeneity of the specimens, we used digital image analysis software developed by us. After that we measured the plastication rate and the melt temperature of the polymer melt because mixing depends on these factors. Our results showed that the screw tips (dynamic mixers) can improve surface color homogeneity but they cause an increase in melt temperature and a decrease in the plastication rate.

scholarly journals DIC TEXTURING-ASSISTED ACCELERATED SOLVENT EXTRACTION OF ACTIVE MOLECULES OF POMEGRANATE PEEL

2016 ◽  
Vol 12 (9) ◽  
pp. 4023-4044
Author(s):  
Karim Allaf ◽  
Khaoula Elaydi ◽  
Ibtisam Kamal ◽  
Ahmed Bedoui
Keyword(s):  
Solvent Extraction ◽  
Radical Scavenging ◽  
Effective Diffusivity ◽  
Bioactive Compound ◽  
Average Diameter ◽  
Processing Parameters ◽  
Accelerated Solvent Extraction ◽  
Raw Material ◽  
Phenol Compounds ◽  
Instant Controlled Pressure Drop

The current work discusses the use of Instant Controlled Pressure Drop (DIC) as a pretreatment texturing stage intensifying phenolic compound extraction from South Tunisian Punicagranatum L. peels in both cases of conventional and Accelerated Solvent Extraction (ASE). Response Surface Methodology (RSM) allowed identifying the effects of DIC processing parameters on the yields of Total Phenol Compounds (TPC), Total Flavonoid (TF), Condensed Tannins (CT), and Hydrolysable Tannins (HT), and antioxidant capacities via 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging capacity and ß-carotene-linoleic acid as responses. Comparative methods were used to evaluate DIC-textured and Raw samples. The results obtained confirmed that appropriate DIC-texturing improved both kinetic and yield of bioactive compound extraction using ASE from Punicagranatum L. peels. Extraction kinetics was studied through Coupled Washing-Diffusion CWD model. The effective diffusivity was identified and quantified ranged from 0.27 to 8.22 against 0.4710-10 m2s-1 for DIC textured and raw material (RM), respectively. DIC swelling enabled solid vegetal material matrix to expand and be more adapted to mass transfer thus increasing extractability of the phenol compounds. Scanning Electron Microscope SEM showed that DIC generated pores with an average diameter of 50 µm.

Sign in / Sign up

Export Citation Format

Share Document