Analysis of the Decomposition using the Short Degradation Technique of Polylactic Acid/Halloysite Nanotube Biocomposites

The article presents results on the decomposition of polylactic acid (PLA)/halloysite nanotube (HNT) biocomposites. Experiments were carried out in laboratory conditions simulating composting in the industrial pile using the so-called short degradation method. In this paper, the effects of the composting process (duration from 30 to 90 days) on the behavior of PLA/HNT composites were studied. In addition, the selected physicochemical properties of PLA/HNTs biocomposites such as the average molecular weight were investigated. The results obtained confirmed the viability of composting PLA with halloysite which contributes to the reduction of plastic waste and the use of this material in technological applications

Effect of the Trunk and Upper Limb Passive Stabilization on Hand Movements and Grip Strength Following Various Types of Strokes—An Observational Cohort Study

Almost half of the patients surveyed report impaired function of the upper limbx and handx after stroke. The effect of the passive trunk and shoulder stabilization on the recovery of coordinated hand movement is unclear. This study examined whether passive stabilization of the trunk and shoulder could improve the functional state of the hands after various types of strokes. It is an observational prospective cohort study conducted at the Rehabilitation Clinic in two parallel groups of patients with four different types of strokes (hemorrhagic and ischemic of the brain, similar to the cerebellum). A total of 120 patients were analyzed. Patients were examined in various positions: sitting without a backrest with the upper limb adjacent to the body, supine with the upper limb perpendicular to the body, and supine with the arm stabilized in relation to the patient’s body. Hand Tutor devices and a hand dynamometer were used for the measurements. The frequency and maximum range of motion as well as the grip strength were measured in three different positions of the trunk and upper limb. Passive stabilization of the trunk and shoulder showed more statistically significant differences in Group II. In group II, both in patients after hemorrhagic stroke (wrist Hz p = 0.019; wrist ROM p = 0.005; Hz F5 p = 0.021; Hz F4 p = 0.016; Hz F3 p = 0.019; Hz F2 p = 0.021) and ischemic stroke (p = 0.001 for wrist Hz, wrist ROM, Hz F from 5 to F2; and ROM F1; ROM F3 p = 0.009; ROM F2 p = 0.010), and hemorrhagic cerebellum, improvement of parameters was observed. Stabilization of the upper limb and passive stabilization of the trunk improved the frequency and range of movements in the radiocarpal joint and in the fingers of patients after stroke, regardless of the type of stroke

Polymer Composite Manufacturing by FDM 3D Printing Technology

3D printing technology was developed nearly 30 years ago. One of its characteristics is that instead of removing materials, 3D printing creates 3D elements directly from CAD models, adding one layer of material on another. This offers a beneficial capability of making complex elements in terms of shape and materials, impossible to be manufactured by traditional methods. Owing to intensive research in recent years, considerable progress has been achieved in the development and commercialisation of new innovative processes of 3D printing by fused deposition modeling (FDM), including printing of composite materials. The study outlines the main methods of creating polymer composite structures using FDM technology

The composting of PLA/HNT biodegradable composites as an eco-approach to the sustainability

The article presents the results of the research related to the decomposition of polylactic acid (PLA)/halloysite nanotube (HNTs) biocomposites into a simple organic form. After manufacturing the nanocomposites, the evaluation of the composting process simulation was conducted using the biodegradation method. First, the selected properties of PLA/HNTs biocomposites, such as density, water absorption, and impact strength were tested. Next, the impact of the composting process on the behavior of PLA/HNTs composites was investigated from 30 to 90 days. Finally, the loss of mass of the composites, hardness, and the structural changes of biocomposites under the composting conditions before and after the composting were evaluated using SEM microscopy. The results showed that the PLA modified by HNT particles has biodegradation-friendly properties and therein is fully suitable for organic recycling. Due to this, in the coming years, it may contribute to the replacement of non-biodegradability polymers, i.e. polyolefins and polyesters, and reduction of plastic packaging wastes

Polymer Composite Manufacturing by FDM 3D Printing Technology

3D printing technology was developed nearly 30 years ago. One of its characteristics is that instead of removing materials, 3D printing creates 3D elements directly from CAD models, adding one layer of material on another. This offers a beneficial capability of making complex elements in terms of shape and materials, impossible to be manufactured by traditional methods. Owing to intensive research in recent years, considerable progress has been achieved in the development and commercialisation of new innovative processes of 3D printing by fused deposition modeling (FDM), including printing of composite materials. The study outlines the main methods of creating polymer composite structures using FDM technology

Study of the Combustion Process for Two Refuse-Derived Fuel (RDF) Streams Using Statistical Methods and Heat Recovery Simulation

This study characterises materials that belong to the group of refuse-derived fuels (RDF). This group of materials regarded as an alternative fuel is derived from industrial, municipal solid and commercial wastes. The aim of this study is to evaluate the quality of waste composition, demonstrate statistically different values and the energy efficiency of the fuel derived from waste. Data on incinerated waste were collected from two different sources. The basic physical and chemical parameters of waste include density and water content. The lower heating value (LHV) of waste, chlorine concentration and ash content of two groups of incinerated waste were also evaluated and compared for a given period of time (one year, with monthly breakdown). Statistical analysis indicated the differences in the combustion of waste groups, visualized by box plots and other diagrams to show the distribution of the results. An analysis of exhaust gas parameters was carried out, both in terms of chemical composition and energy parameters. The RDF combustion process was presented through simulations for the adopted conditions of heat recovery. It was found that for each kilogram of RDF, about 3.85 kWh (13,860 kJ) of heat can be obtained. The combustion process was simulated using Aspen Plus software

Study of the Combustion Process for Two Refuse-Derived Fuel (RDF) Streams Using Statistical Methods and Heat Recovery Simulation

This study characterises materials that belong to the group of refuse-derived fuels (RDF). This group of materials regarded as an alternative fuel is derived from industrial, municipal solid and commercial wastes. The aim of this study is to evaluate the quality of waste composition, demonstrate statistically different values and the energy efficiency of the fuel derived from waste. Data on incinerated waste were collected from two different sources. The basic physical and chemical parameters of waste include density and water content. The lower heating value (LHV) of waste, chlorine concentration and ash content of two groups of incinerated waste were also evaluated and compared for a given period of time (one year, with monthly breakdown). Statistical analysis indicated the differences in the combustion of waste groups, visualized by box plots and other diagrams to show the distribution of the results. An analysis of exhaust gas parameters was carried out, both in terms of chemical composition and energy parameters. The RDF combustion process was presented through simulations for the adopted conditions of heat recovery. It was found that for each kilogram of RDF, about 3.85 kWh (13,860 kJ) of heat can be obtained. The combustion process was simulated using Aspen Plus software