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BACKGROUND: Heart rate (HR) indicates the number of beats per minute (bpm) of the heart, while heart rate variability (HRV) indicates the temporal fluctuation of the intervals between adjacent beats (NN). HRV expresses neuro-cardiac activity and is generated by heart-brain interactions and dynamics related to the function of the autonomic nervous system (ANS) and other components (e.g., body and ambient temperature, respiration, hormones, blood pressure). We are carrying out a series of experimental investigations with the aim of studying HRV in student pilots during training.CASE REPORT: For this purpose, we used a Holter electrocardiograph equipped with three channels and five electrodes positioned on the chest of the subject who participated in our investigation. The case report refers to a student pilot who, during a flight mission with the instructor, had to face a forced landing and a flap failure. We report data based on analysis of the time domain and frequency domain related to operations on the ground before the flight, during the flight, and on the ground after the flight.DISCUSSION: Our initial conclusion is that the extent of HRV constitutes an “energy store” for better cardiac performance in eustress activities. During advanced tasks, the “Total Power” of the heart decreases because the RR intervals are forced toward low values, where the heart is less able to be modulated by its many controllers. Furthermore, this experimental protocol can be useful to flight instructors for the training process of student pilots.Li Volsi G, Monte IP, Aruta A, Gulizzi A, Libra A, Mirulla S, Panebianco G, Patti G, Quattrocchi F, Bellantone V, Castorina W, Arcifa S, Papale F. Heart rate variability of a student pilot during flight training. Aerosp Med Hum Perform. 2023; 94(6):475–479.

Quality evaluation of micro injection molded products is a complex task, in particular when instruments basing on contact methods are used and issues in measurements could arise due to the contact tool dimension not fitting well with extremely narrow features. Therefore, in these cases, optical methods may be preferred for the evaluation of molded products’ dimensions and surface quality, especially for parts devoted to applications requiring functional purposes. In this context, the present paper proposes the use of surface parameters as a quality index for the evaluation of both the micro injection molding process and the resulting products. To this aim, two experimental procedures were implemented to allow for: (i) the evaluation of the most suitable surface parameters identified in relation to the process parameters; (ii) comparisons of the surface parameters findings with those obtained by classic dimensional quantity via a designed experimental plan (DoE). The results show that the surface parameters, evaluated in critical areas of the components, can ensure reliable estimates for the surface quality of the molded parts and can be preferred in comparison to linear measurements.

Heart rate (HR) indicates the number of beats per minute (bpm) of the heart, while heart rate variability (HRV) indicates the temporal fluctuation of the intervals between adjacent beats (NN). HRV expresses neuro-cardiac activity and is generated by heart-brain interactions and dynamics related to the function of the Autonomous Nervous System (ANS) and other components (body and ambient temperature, respiration, hormones, blood pressure). The flight activity, especially during training, provides for a prolonged state of alert of the student pilot, as well as careful management of the flight and simultaneous planning of the next steps, with attention to the unusual conditions and emergencies that may occur during all various stages. HRV can provide a good reference index for estimating the degree of evolution of the training process of student pilots and a valid tool for some indications of a physiological as well as clinical nature. To investigate this issue, we started a series of experiments, still ongoing, by coupling the flight task times of student pilots with changes in their HRV. Before each experimental session, the participating pilot student was equipped with five electrodes, three-channel Holter (ECG BIOMEDICAL, BI9100). For this purpose, we have defined three-time phases: ground flight operations (bfo), in-flight operations (dfo) and post-flight ground operations (afo). The HRV analysis was carried out using the time domain and frequency domain parameters. As regards the mean of the RR intervals in the dfo, an increase was observed in 29% of the sample, while a decrease was observed in the remaining 71%, compared to that in the bfo. The analysis of the data relating to very low frequencies (VLF), low frequencies (LF) and high frequencies (HF) in the sample highlighted the values indicated below. In dfo, an increase in VLF values in 18% of the sample and a decrease in 82% in the remaining 71% compared to what was observed in bfo. LF values in dfo increased in 29% of the sample and decreased in the remaining 71%, compared to bfo. Finally, the HF, in dfo increased in 29% and decreased in 71% of cases, compared to the values of the bfo. Additional significant differences were found between the cases in which the RR intervals decreased in the dfo compared to the bfo, and those in which the RR intervals increased in the dfo compared to the bfo. In conclusion, the observed data lead to reconsider some physiological correlates of the different components involved in the determinism of HRV of a subject who carries out intense psychophysical activity for a certain period. In fact, it is necessary to evaluate the role of the ANS, in its various divisions (parasympathetic, sympathetic, and enteric), as well as the activity of the baroreceptors, the respiratory cycle (respiratory sinus arrhythmia), the thermoregulatory and hormonal factors within the short and medium tasks term.

At the present time, there is a growing interest in additive manufacturing (AM) technologies and their integration into current process chains. In particular, the implementation of AM for tool production in micro injection molding (µ-IM), a well-established process, could introduce many advantages. First of all, AM could avoid the need for the time-consuming and expensive fabrication of molds for small series of customized products. In this work, the feasibility, quality, and reliability of an AM/µ-IM process chain were evaluated by designing and fabricating mold inserts for µ-IM by stereolithography (SLA) technology, the mold inserts were characterized and tested experimentally. The selected geometry is composed of four thin cavities: This particular feature represents an actual challenge for both the SLA and µ-IM perspective due to the large surface-to-volume ratio of the cavity. Two different materials were used for the mold fabrication, showing sharply different performance in terms of endurance limit and cavity degradation. The obtained results confirm that the µ-IM process, exploiting an SLA fabricated mold insert, is feasible but requires great accuracy in material choice, mold design, fabrication, and assembly.

Micro-applications, especially in biomedical and optical sectors, require the fabrication of thin polymeric parts which can be commonly realized by micro-injection molding process. However, this process is characterized by a relevant constraint regarding the tooling. Indeed, the design and manufacturing of molds could be a very time-consuming step and so, a significant limitation for the rapid development of new products. Moreover, if the design displays challenging microfeatures, their realization could involve the use of more than one mold for the fabrication of a single thin part. Therefore, proper integration of different manufacturing microtechnologies may represent an advantageous method to realize such polymeric thin microfeatures. In this work, a micromanufacturing process chain including stereolithography, micromilling, and micro-injection molding is reported. The mold for the micro-injection molding process was fabricated by means of stereolithography and micromilling, which allowed us to produce low-cost reconfigurable modular mold, composed of insert support and a removable insert. The assessment of the proposed process chain was carried out by evaluating the dimensions and the surface finishing and texturing of the milled mold cavities and molded components. Finally, a brief economic analysis compares three process chains for fabricating the micromold showing that the proposed one reduces the manufacturing cost by almost 61% with the same production time.

In this work, the moldability via micro-injection molding (μIM) of nano-filled polyamide 6 (PA6) based systems and the microstructural characteristics of the micro-injected parts were investigated and compared to those observed via traditional injection molding (IM). Two types of nano-fillers, different in nature and geometry, were examined, namely carbon nanotubes and silicate layers. The presence of nano-fillers did not impair the mold replication capability of PA6 in the μIM process. A micro-rib and a standard dumbbell specimen for tensile tests were used as reference micro- and macro-injected part, respectively. Transmission Electron Microscopy, Wide and Small Angle X-ray Scattering and Differential Scanning Calorimetry analyses showed that, due to the different thermomechanical histories during μIM and IM, the micro- and the macro-parts have different microstructures, influenced also by the filler type. Both nano-filler dispersion and PA6 crystallinity were influenced.

The increasing demand for small and cheap parts is boosting the development of reliable micro-system technologies. Fabrication process capabilities should expand to encompass a wider range of materials and geometric forms, which can satisfy the specific requirements of new emerging micro-products, and ensure the compatibility of new materials and processing technologies. Polymeric composites are very promising materials, since they offer new combinations of properties not available in traditional homogeneous materials. Because of their advantageous light weight, high strength, fatigue life, and corrosion resistance, they are forecast to replace conventional materials in several applications. Among the plastic process technologies, injection moulding is one of the key technologies for manufacturing miniaturised components due to its mass production capability and relatively low production cost. Micro-injection moulding allows to transfer micron and even submicron precision features to small products. Since final product properties strongly depend on materials and production processes and parameters, the process conditions of compounding as well as of product manufacturing have to be carefully studied and controlled. This is particularly important for the manufacturing of micro-products, since, at the micro-scale, some phenomena negligible at the macro-scale (as hesitation effect or capillarity forces for examples) can become important. However, only few studies concern the micro-injection of nanocomposites. Therefore, in this paper the micro-injection of two composites made of polyoxymethylene and carbon nanotubes has been studied. First, the electrical properties of the compounds have been measured; the fillers are dispersed in the matrix and form a network that dramatically increases the conductivity of the composites in comparison with the pristine resin. Then the compounds have been injected using a micro-injection machine and the components have been analysed. The mechanical analysis, based on tensile tests and dynamic-mechanical experiments on miniaturised dog-bone specimens, shows a slight reinforcing effect of the filler; however, the ductility is considerably reduced. This is likely due to a scarce adhesion of the carbon nanotubes and the polymer and the presence of some agglomerates. Moreover, as expected, the mould temperature affects the mechanical properties of the specimens, probably due to its effect on the internal structure of the solidified materials. The dimensional analyses carried out on micro-rib specimens show that replication capability is increased by the presence of the filler and using high values of the process parameters. Finally, microscopic analyses have been done in order to verify the dispersion and orientation of the fillers in the compounds. These effects have been observed only when high shear rates are involved.

Currently, the increasing interest in the study of Polylactic acid (PLA) polymer has been motivated by the potential of such material for consumer and biomedical applications. PLA is a thermoplastic polymer, biodegradable, compostable and deriving from renewable natural sources as starch and sugar. Injection molding is the most widely used process for thermoplastic micro-featured parts for to its capacity to manufacture low-cost and high repeatable micro-parts. The use of PLA for injection molded micro components is still not well stabilized due to the slow crystallization kinetics, not suitable for high performance applications. In this work, preliminary experimental studies have been performed to analyze the filling ability of PLA in a meso and a micro parts using different molding conditions to evaluate process parameters influence. The experiments results are discussed in the paper and show that injection molding proved to be suitable for meso-micro PLA product manufacturing.

Additive Manufacturing (AM) technologies have recently emerged as key technologies to be integrated in current process chains. In particular, AM technologies could be successfully applied for molds and inserts fabrication for small batches production of components and microcomponents. In terms of economy and sustainability, the AM offers several advantages with respect to traditional manufacturing technologies for molds and inserts fabrication, such as waste reduction, minimized energy consumption, reduced cycle time and time to market. In this work, a thin cavities mold insert was manufactured via inverted (bottom-up) stereolitography (SLA) and tested via micro-injection molding in order to assess the feasibility of the SLA/?-IM (Injection Molding) process chain. The designed geometry is composed by four thin cavities: this particular feature represents the actual challenge, due to the large surface to volume ratio that characterizes the sample. Design rules for AM have been applied in order to fulfill injection molding issues and ensure a longer mold insert duration. The mold insert cavities have been characterized to evaluate the achieved dimensional and geometrical precision showing a quite good geometry accuracy in thickness; the mold insert geometrical deviation, which could prevent the correct assembly of the insert into the mold, have been measured too. Finally, a short-series of about 30 molding cycles has been carried out evaluating the capacity of filling the thin cavities and the capability of SLA mold insert.

The surface to volume ratio in micro injection molding is quite large and this makes interfacial phenomena particularly crucial for the effectiveness of the process. This criticality is more evident for thin parts molding, where the influence of roughness on the thermal boundary conditions is not negligible. In this case, the contact between polymer and mold significantly affects the heat transfer at the interface and consequently it strongly influences the polymer melt flow behavior. In this paper, the effects of the polymer-mold interface on polymer flow were experimentally investigated. In particular, the filling of a representative micro part with a thickness of 100 μm was studied in relation to surface roughness and mold wettability. The results showed that the state of the polymer-mold interface plays a fundamental role in the filling of thin-wall micro injection molding. In particular, the flow length increases with both the mold roughness and the contact angle between the molten polymers and the cavity surface.

Many research efforts have gone in the production of carbon nanotubes (CNT) composites for functional and structural applications and many processing methodologies have been experimented. Twin-screw extrusion appears to be the most suitable way from the perspective of production scale up and commercialization of these composites. At the same time, micro-injection molding process is considered as the key manufacturing technology for the mass production of miniaturized components and devices. Despite the massive literature about nanocomposites and microinjection molding process, few articles focus on the interaction between the compounding process and the following micro-injection molding transformation processes. This article aims at analyzing the influence of the screw configuration used in compounding process on the rheological and technological properties of the resulting nanocomposites. Two different combinations of screw elements have been tested to incorporate CNTs in two different resins: LCP (liquid crystal polymer) and POM (polyoxymethylene) typically used in micro-injection molding. The effects of the process set up have been observed studying first the rheology and then the moldability of nano-compounds microinjected ribs with high aspect ratio. The nanofiller dispersion has been evaluated via light and transmission electron microscopy. The results confirm that, the screws show different capacity at promoting the dispersion of the nanofiller, which affects the moldability of micro-injected CNT nanocomposites. The viscosity of the polymer seems a critical factor as well, because it influences first the dispersion of CNT bundle during extrusion and then the injection moldability of the composites in the micro-channels. POLYM. COMPOS., 2015. © 2015 Society of Plastics Engineers

Due to its ability to produce low-cost and high repeatable micro-polymeric parts, micro-injection molding is emerging as one of the most promising enabling technologies in many different fields. When approaching the micro-scale, different issues related to the process should be addressed, especially as the thickness of the cavities becomes very thin. In particular, the mold roughness affects the surface quality of the micro-components produced, like in macro-molding, but this could also encompass the complete filling of the parts. The main objective of the present paper is to evaluate the roughness influence of the mold on the non-Newtonian fluid flow during the micro-injection process in thin micro-cavities where the mold surface condition could affect the process due to the phenomena neglected in macro- or mesoscale as less important boundary conditions. The part design was properly conceived in order to neglect the effect of dimensions and geometry and to highlight the roughness contribution during the filling phase. The experimentation was performed using cavities with different roughness values and decreasing depths from 200 to 50 μm, considerably lower than 250 μm found in literature and manufactured by the micro-electrical discharge machining (μ-EDM). The results of the experiments are discussed and show that cavity-surface roughness affects the process as the molding scale is decreased. In particular, in thin cavities, higher surface roughness promotes the filling of component.

Achieving high quality parts is a crucial task for the micro injection moulding process due to the sensitive nature of applications as medical and aerospace. In this work, simulation and an experimental study are performed to analyse the effect of four main parameters (injection speed, melt and mould temperature, and holding pressure) on replicating capability of a micro feature by injection moulding process that is the main focus of the present paper. This work also assesses the performance of a screwless-two plungers micro moulding machine in processing polyoximethilene (POM) and liquid crystal polymers (LCP). Results show that mould temperature and injection speed are the most effective parameters on replicating capability respectively for POM and LCP and high parameters setting improved the dimensions of the feature and thus the quality. For LCP, achieving process reproducibility is more difficult than for POM even if the obtained replication fidelity is considerably higher.

Due to its ability to produce low-cost and high repeatable micro polymeric parts, injection moulding of micro components is emerging as one of the most promising enabling technologies for the manufacturing of polymeric micro-parts in in many different fields, from IT to Healthcare, to Medicine. However, when approaching the micro-scale, different issues related to the process should be addressed, especially as the depth of the mould cavity becomes very thin. In particular, the mould roughness could affect the surface quality of the produced micro components, like in macro moulding, as well as the complete filling of the parts. Although micro-injection moulding process has been extensively studied, further research on the effect of mould roughness conditions and on non-Newtonian fluid flow in micro-cavities are required. This will shed a light and open up new paths for a deeper understanding of the moulding scenario. The main objective of the present paper is the evaluation of the influence of the mould roughness on the polymer flow during micro injection moulding process. The test parts have been realized in POM material and have thickness lower than 250 μm. The test part design has been properly conceived in order to neglect the effect of dimensions and geometry and to highlight the roughness contribution during the filling phase of micro injection moulding process. The experimentation has been performed considering cavities with different roughness values (3 levels) and decreasing depths (3 levels), for a total of nine test parts manufactured by micro-electrical discharge machining process (μ-EDM). The results of the experiments are discussed in the paper and show that cavity surface roughness affects the injection process as the moulding scale level is decreased. In particular, when the cavity depths are reduced, higher surface roughness promotes the filling of components and this finding could be ascribed to the increase of wall slip effect.

This paper reports on design, fabrication, and characterization of a microfilter to be used in biomedical applications. The microfilter, with mesh of 80 μm, is fabricated by micro-injection molding process in polymeric material (polyoxymethylene (POM)) using a steel mold manufactured by micro-electrical discharge machining process. The characteristics of the filter are investigated by numerical simulation in order to define a suitable geometry for micro-injection molding. Then, different process configurations of parameters (melt temperature, injection velocity, mold temperature, holding pressure and time, cooling time, pressure limit) are tested in order to obtain the complete part filling via micro-injection molding process preventing any defects. Finally, the component is dimensionally characterized and the process parameters optimized to obtain the maximum filtration capacity.

This paper reports on fabrication and characterization of a micro-filter for hearing aid, dialysis media and inhaler. The micro-feature specifications consist in a diameter of 2.3 mm, a thickness of 0.2 mm and it is composed by a mesh with grid of 80 μm and ribs with width of 70 μm. The proposed micro-filter is fabricated by micro injection moulding process adopting a steel mould manufactured by micro Electrical Discharge Machining process (micro EDM). Different polymeric materials (POM, HDPE, LCP), particularly indicated for the injection moulding applications due to their flowability and stability, are tested and evaluated in relation to the process replication capability. Since the polymer micro-filter is made of a complex grid of micro-ribs, the injection moulding process must ensure complete filling of the micro-parts, preventing any defects (i.e. premature solidification, incomplete filling, flash and air traps). To this aim, different system parameters configurations (melt and mould temperature, injection velocity, holding time and pressure, cooling time, pressure limit) are tested for obtaining acceptable part in all polymers grade. Finally, the component is dimensionally characterized by confocal microscopy and its filtration capacity is then verified. Although the feature complexity was high, the results showed that the object could be successfully replicated by filling completely the micro cavities with two of them: POM and HDPE. The most significant parameters influencing the part filling were the mould temperature and the injection velocity. These findings allow to further optimize the micro-injection process parameters to obtain a high quality product.

This paper reports on design, fabrication and characterization of a micro-filter for hearing aid, dialysis media and inhaler. The microfilter is fabricated by micro injection moulding process in polymeric material (Polyoxymethilene - POM) using a steel mould manufactured by micro electrical discharge machining process. A novel filter configuration is proposed and, in the design step, the characteristics of the filter are investigated by numerical simulation in order to define a suitable geometry for micro-injection moulding. Then, different process configuration of parameters (melt and mould temperature, injection velocity, holding time and pressure, cooling time, pressure limit) are tested in order to obtain the complete part filling. Finally the component is dimensionally characterized and the process parameters optimized to obtain the maximum filtration capacity.

Nowadays, the study of polymer nanocomposites is an active area of materials development because nanofillers and in particular Multi-Wall Carbon Nanotubes (MWCNTs) can significantly improve or adjust the properties of the materials into which they were incorporated such as optical, electrical, mechanical and thermal properties. MWCNTs have been adopted in quite a number of applications, but advancements in their properties are needed for spreading their potential. Moreover their behaviour and filling properties in micro injection moulding process have still to be studied. Therefore, in this work, experimental and statistical studies were performed to analyze the parameters effect on replicating capability of micro parts manufactured in POM/MWCNT by micro injection moulding process. Two compounds with different filler fraction (3 and 6 wt%) were tested and processed with different conditions and their operating range have been pointed out and compared with that of pristine POM (PolyOxyMethilene). The results show that the filler content has the effect to change slightly the operative range of the micro injection process parameters and to increase the replicating capability. The most effective parameters on replicating capability of micro ribs, evaluated by a dimensional index, are the mould temperature for the POM/MWCNT 3% and injection velocity for the 6% filler fraction.

Oggetto del presente studio è lo stampaggio ad iniezione di micro feature (definiti micro ribs) con due polimero: il Poliossimetilene (POM) ed il Liquid Cristal Polymers (LCP) sia tal quali che caricati con nanotubi di carbonio al 3% e al 6%. L'estrusione è avvenuta con due condizioni di processo (d'ora in poi indicate come viti1 e viti2) nella sede di ITIA Milano. Si vuole valutare come la carica nelle varie percentuali e le condizioni di processo di estrusione a parità di carica possano influire sul processo di micro stampaggio. Tale studio è stato effettuato attraverso una ispezione sia qualitativa che quantitativa dei campioni prodotti.

Il presente documento vuole aggiornare lo stato dell'arte sugli studi di rugosità nel processo di stampaggio per micro iniezione. Allo scopo si riportano i riferimenti ed i risultati dei lavori più rappresentativi illustrati precedentemente (sezione 1), gli aggiornamenti individuati con le tendenze di ricerca su questo argomento (sezione 2). Infine, si valutano i possibili sviluppi (sezione 3).

Allo scopo di verificare la posizione dei fori per l'alloggiamento degli inserti nello stampo, in particolare la loro centratura, si sono misurate le distanze di interesse sia con il microscopio confocale CSM 700 della Zeiss che ricavate dalla nuvola di punti ottenuta dalla scansione dello stampo realizzata presso il PoliMi.

Allo scopo di testare la validità della misurazione ottica per la rugosità, si sono eseguite misure con il microscopio confocale della Zeiss CSM 700 su un provino normato di rugosità nota.

Il report presenta l'attività di stampaggio di piattine in PMMA, la sperimentazione effettuata, il range operativo dei parametri di processo individuati, la misurazione di un campione prodotto.

Si è cercata la finestra operativa di stampaggio per il policarbonato prodotto dalla BAYER con il nome Makrolon 2458

Si riportano in questo documento alcune misure dello stampo, usato per il micro stampaggio ad iniezione, prese attraverso il microscopio confocale CSM700 della ZEISS. Le immagini utilizzate per le misure sono state acquisite attraverso la ricomposizione panoramica (pacthwork), via software proprietario, di frame successivi lungo gli assi x ed y ed in scansione lunga l'asse z.

The increasing demand for small and even micro scale parts is boosting the development of reliable micro system technologies. Micro-fabrication process capabilities should expand to encompass a wider range of materials and geometric forms, by defining processes and related process chains that can satisfy the specific functional and technical requirements of new emerging multi-material products, and ensure the compatibility of materials and processing technologies throughout these manufacturing chains. Micro injection moulding is the process of transferring the micron or even submicron precision of microstructured metallic moulds to a polymeric products. It represents one of the key technologies for micro manufacturing because its mass production capability and relatively low production cost. Polymers have relatively low cost, and offer good mechanical and thermal strength, electrical insulation, optical transparency, chemical stability and biocompatibility. In this work the authors investigate the micro injection moulding process parameters on the overall quality of a miniaturized dog-bone shaped specimen. The aim of the experimentation is to calibrate the process and set the machine for the correct filling of the component. A set of injection parameters are selected for study by experimental plan and simulation tool and then discussed. Simulation results are used to better understand the polymer flow behaviour during the filling phase. A commercial software is used and input data, collected during the micro injection moulding process, are included using as performance indicators flow front position and moulded mass. Process simulation can provide, at the present time, mostly qualitative input to the designer and process engineer. Two different polymers materials are tested and evaluated in relation to the process replication capability: Polyoxymethylene (POM) and Liquid Cristal Polymer (LCP). Finally, the moulding factors with significant statistical effects are identified. The holding pressure and holding time for POM and the holding pressure and injection velocity for LCP show the highest influence on achieving high part mass.

In recent years, there is an increasing demand for small and even micro scale parts and this trend towards miniaturization makes the micro system technologies of growing importance. Microfabrication process capabilities should expand to encompass a wider range of materials and geometric forms, by defining processes and related process chains that can satisfy the specific functional and technical requirements of new emerging multi-material products, and ensure the compatibility of materials and processing technologies throughout these manufacturing chains. Example technologies to be investigated either individually or in combination are technologies for director rapid manufacturing, energy assisted technologies, microreplication technologies, qualification and inspection methods, functional characterisation methods and integration of "easy and fast" on-line control systems.

A desert dust episode in June 2007 and its radiative effects on the energy budget have been studied at three Italian stations (Rome, Lecce and Lampedusa) with the aim of investigating the interactions with different conditions and aerosol types over the Mediterranean. The three sites are representative for urban (Rome), sub-urban/rural (Lecce), and marine (Lampedusa) environment, respectively in the central Mediterranean region. Measured ground-based column-averaged aerosol optical properties and aerosol extinction profiles were used to initialize the MODTRAN4 radiative transfer model. The radiative transfer model was used to estimate the shortwave aerosol radiative forcing ( ARF ) and its forcing efficiency ( FE ) at two different solar zenith angles (20° and 60°) in the 280–2800 nm spectral range. The goal was to investigate the role of different aerosol types in the atmospheric boundary layer on the radiative budget during a dust event. During the event the aerosol optical depth was moderately high and similar at the three stations, with a maximum value of about 0.6. The Angstrom exponent was found to increase with the distance from the source (0.21, 0.36, and 0.43 at Lampedusa, Rome, and Lecce, respectively). Differences in the aerosol optical properties were observed, also depending on the aerosol type assumed in the boundary layer. The estimated direct aerosol forcing appears to depend on the changes in aerosol properties and to the surface albedo. The results show that the desert dust produces a cooling effect at both surface (largest ARF of −224 W m −2 at 20° solar zenith angle at Rome) and top of the atmosphere (largest ARF of −19 W m −2 at 20° solar zenith angle at Lecce). The cooling is largest in the rural and smallest in the marine environment. The surface forcing efficiency appears to be strongly affected by the aerosol absorption in the BL. Large differences exist between our results and the FE determinations by AERONET, derived considering a single layer with homogeneous optical properties and prescribed vertical distribution. The FE deviations are around 20, 60, and 40% at the surface, TOA, and in the atmosphere, respectively. These results suggest that the detailed description of the vertical distribution of the aerosol properties is needed for an accurate determination of its radiative effects.

This report presents and discusses the evaluation of the software modules: Z-Stack and Topography (1) in term of time consuming for images acquisition, accuracy and reliability in measuring vertical dimension and roughness surface of the examined objects.

Due to its high efficiency for the large scale production of polymeric parts, micro injection moulding is one of the key technologies of the new millennium. Although a lot of researches have been conducted to identify the most effective processing conditions for micro injection moulding, the comprehension of the influence of all parameters on the quality, the properties and the reliability of the moulded parts is still an issue. In this context, this study aims to evaluate the effects of the micro injection moulding process conditions on the tensile properties of micro parts, investigating the influence of three main process parameters: the injection speed, the mould temperature and the melt temperature. A full factorial plan has been applied to study the contributions of these parameters and a second study has been performed to understand the synergic interaction between the two temperatures on the tensile strength. Due to its high level of potential crystallinity, a typical semi-crystalline thermoplastic resin was used in the experiments. The results of the analysis showed a great influence of the mould temperature (Tmould ) on the ultimate tensile strength and of the melt temperature (Tmelt ) on the deformation at the point of breaking; whereas the injection speed was significant on the overall mechanical performance. A new studied factor (Tmelt -Tmould ) could affect the resulting molecular structure and consequently the mechanical behaviour, but itself is not sufficient to thoroughly explain the observed behaviour. Moreover, the visual inspection of the deformation mechanism at break shows three distinctive trends demonstrating the great variability of the mechanical properties of micro-injected specimens due to process conditions.Copyright © 2011 by ASME

Ground-based particulate matter (PM) samplers, an XeF Raman lidar operating in the framework of the European Aerosol Research Lidar Network (EARLINET), and a sun/sky radiometer operating in the framework of the Aerosol Robotic Network (AERONET) have been used to characterize vertical profiles, optical and microphysical properties, and chemical composition of aerosols during the 29 June–1 July 2005 dust outbreak that occurred over the central-eastern Mediterranean. Aerosol backscatter coefficient, total depolarization, and lidar ratio vertical profiles revealed that a well-mixed dust layer extending from ∼0.5 to 6 km was present over southeastern Italy on 30 June. Sun/sky radiometer measurements revealed a bimodal lognormal size distribution during all measurement days. The particle volume distribution was found to be well correlated either to the PM mass distribution measured at ground by a seven-stage cascade impactor and to the fine to total suspended PM mass ratio measured by ground-based PM samplers. Scanning electron microscopy and ion chromatography analyses on PM samples revealed that coarse-mode aerosols were mainly made of carbonate, aluminum-silicate, and sea salt particles. Carbon, sulfate, and nitrate particles were the main components of fine-mode aerosols representing more than 50% of the total aerosol load; the significant role of fine-mode anthropogenic particles during a dust event is highlighted. Finally, the potential capabilities of complementary measurements by passive and active remote sensing techniques and in situ observations to retrieve the vertical distribution of the particle number and mass concentration are analyzed and discussed.