Operator's manual : grenade launcher, 40-mm, M203 (1010-00-179-6447).

"December 1984."

Direct and general support maintenance manual for armament subsystem, helicopter, 40 millimeter grenade launcher, M5 (1010-738-5811) (used on UH-1B or UH-1C helicopters).

"21 May 1973."

Aviation unit maintenance manual for armament subsystem, helicopter, 40 millimeter grenade launcher, M5 (1010-00-738-5811) (used on UH-1B or UH-1C helicopters).

"March 1973."

Operator's manual : 40-mm grenade launcher M79, (1010-00-691-1382).

"Reprint which includes current pages from changes 1 and 2"--Cover.

Using organoclay to promote morphology refinement and co-continuity in high-density polyethylene/polyamide 6 blends - Effect of filler content and polymer matrix composition

We investigate the gradual changes of the microstructure of two blends of high-density polyethylene (HDPE) and polyamide 6 (PA6) at opposite composition filled with increasing amounts of an organomodified clay. The filler locates preferentially inside the polyamide phase, bringing about radical alterations in the micron-scale arrangement of the polymer phases. When the host polyamide represents the major constituent, a sudden reduction of the average sizes of the polyethylene droplets was observed upon addition of even low amounts of organoclay. A morphology refinement was also noticed at low filler contents when the particles distributes inside the minor phase. In this case, however, keep increasing the organoclay content eventually results in a high degree of PA6 phase continuity. Rheological analyses reveal that the filler loading at which the polyamide assembles in a continuous network corresponds to the critical threshold for its rheological transition from a liquid- to a gel-like behaviour, which is indicative of the structuring of the filler inside the host PA6. On the basis of this finding, a schematic mechanism is proposed in which the role of the filler in driving the space arrangement of the polymer phases is discussed. Finally, we show that the synergism between the reinforcing action of the filler and its ability to affect the blend microstructure can be exploited in order to enhance relevant technological properties of the materials, such as their high temperature structural integrity.

Pyrolysis of polyamide 6 under catalytic conditions and its application to reutilization of carpets

ε-caprolactam is a monomer of high value. Therefore, the chemical reutilization of polyamide 6 containing carpets for ε-caprolactam recovery offers some economic benefit and is performed on a technical scale with the help of the Zimmer-process. By this process polyamide 6 is depolymerized with steam and phosphoric acid. An alternative to this process is the thermal depolymerization - catalyzed or non-catalyzed. To investigate this alternative in more detail, the formal kinetic parameters of (i) the thermal depolymerization of polyamide 6, (ii) the thermal depolymerization in presence of sodium/potassium hydoxide, and (iii) the thermal depolymerization in presence of phosphoric acid are determined in this work. Based on the kinetics of the catalyzed or non-catalyzed depolymerization a stepwise pyrolysis procedure is designed by which the formation of ε-caprolactam from polyamide 6 can be separated from the formation of other pyrolysis products. © 2001 Elsevier Science B.V.

Effect of the processing conditions on the microstructure and properties of rotational molded polyamide 11

Rotomolded containers for solvents and hydrocarbons require the use of high-permeability resins such as polyamide (PA). The published studies with this material are very scarce. In this work, a commercial grade of PA11 was rotational-molded using different processing temperatures and characterized with a range of techniques. The study aims at investigating the influence of the processing conditions on the microstructure and properties of molded parts. The results showed that the spherulitic morphology and the mechanical properties are affected by the processing temperature, the optimum processing range being between 220°C and 240°C. Overheating causes a decrease of the impact strength and a severe increase in the formation of pinholes at the outer surface due to polymer degradation and formation of volatile products. The thermo-oxidation reactions occurring at the inner surface of the samples result in the formation of products that absorb in the UV and visible light regions and cause the microhardness and the melt viscosity of the material to increase. The extent and severity of the degradation at the inner surface may be easily assessed by fluorescence microscopy. © 2008 Wiley Periodicals, Inc.

Effect of cooling rate on properties of plasma nitrided AISI 1010 steel

In this work, AISI 1010 steel samples were plasma nitrided into 20% N 2 100 Pa and 400 Pa for N 2 and H 2 , respectively), temperatures of 500 and 580 °C, during 2 h. Three different procedures for cooling were accomplished after nitriding. In the first procedure the cooling occurred naturally, that is, the sample was kept on substrate holder. In the second one the sample was pulled off and cooling in a cold surface. Finally, in the third cooling process the sample was pulled off the substrate holder down into special reservoir filled with oil held at ambient temperature. The properties of the AISI 1010 steel samples were characterized by optical and electron microscopy, X-ray diffraction, Mössbauer spectroscopy and microhardness tests. Thermal gradient inside the sample kept on substrate holder during cooling process was measured by three inserted thermocouples at different depths. When samples were cooled rapidly the transformation of ϵ-Fe 2 − 3 N to γ′-Fe 4 N was inhibited. Such effect is indicated by the high concentration of ϵ-Fe compound zone. To get solid state solution of nitrogen in the diffusion zone, instead of precipitates of nitride phases, the cooling rate should be higher than a critical value of about 0.95 °C/s. When this value is reached at any depth of the diffusion zone, two distinct diffusion zones will appear. Temperature gradients were measured inside the samples as a consequence of the plasma treatment. It's suggested the need for standardization of the term “treatment temperature” for plasma treatment because different nitrided layer properties could be reported for the same “treatment temperature”.

Nanofiltration membranes modified with aromatic polyamide dendrimers active layers

This thesis describes the modification of the commercial TFC-S nanofiltration membrane with shape-persistent dendritic architectures. Amphiphilic aromatic polyamide dendrimers (G1-G3) are synthesized via a divergent approach and used for membrane modification by direct percolation. The permeate samples collected from the percolation experiments are analyzed by UV-Vis spectroscopy to instantly monitor the influence of dendrimer generations on percolation behaviors and new active layer formation. The membrane structures are further characterized by Rutherford backscattering spectrometry (RBS) and atomic force microscopy (AFM) techniques, suggesting a low-level accumulation of dendrimers inside the TFC-S NF membranes and subsequent formation of an additional aramide dendrimer active layer. Thus, all the modified TFC-S membranes have a double active layer structure. A PES-PVA film is used as a control membrane showing that structural compatibility between the dendrimer and supports plays an important role in the membrane modification process. The performance of modified TFC-S membrane is evaluated on the basis of rejection abilities of a variety of water contaminants having a range of sizes and chemistry. As the water flux is inversely proportional to the thickness of the active layer, we optimize the amount of dendrimers deposited for specific contaminants to improve the solute rejection while maintaining high water flux.

Effect of cooling rate on properties of plasma nitrided AISI 1010 steel

In this work, AISI 1010 steel samples were plasma nitrided into 20% N 2 100 Pa and 400 Pa for N 2 and H 2 , respectively), temperatures of 500 and 580 °C, during 2 h. Three different procedures for cooling were accomplished after nitriding. In the first procedure the cooling occurred naturally, that is, the sample was kept on substrate holder. In the second one the sample was pulled off and cooling in a cold surface. Finally, in the third cooling process the sample was pulled off the substrate holder down into special reservoir filled with oil held at ambient temperature. The properties of the AISI 1010 steel samples were characterized by optical and electron microscopy, X-ray diffraction, Mössbauer spectroscopy and microhardness tests. Thermal gradient inside the sample kept on substrate holder during cooling process was measured by three inserted thermocouples at different depths. When samples were cooled rapidly the transformation of ϵ-Fe 2 − 3 N to γ′-Fe 4 N was inhibited. Such effect is indicated by the high concentration of ϵ-Fe compound zone. To get solid state solution of nitrogen in the diffusion zone, instead of precipitates of nitride phases, the cooling rate should be higher than a critical value of about 0.95 °C/s. When this value is reached at any depth of the diffusion zone, two distinct diffusion zones will appear. Temperature gradients were measured inside the samples as a consequence of the plasma treatment. It's suggested the need for standardization of the term “treatment temperature” for plasma treatment because different nitrided layer properties could be reported for the same “treatment temperature”.

Reduction rules for YAWL workflows with cancellation regions and OR-joins

As the need for concepts such as cancellation and OR-joins occurs naturally in business scenarios, comprehensive support in a workflow language is desirable. However, there is a clear trade-off between the expressive power of a language (i.e., introducing complex constructs such as cancellation and OR-joins) and ease of verification. When a workflow contains a large number of tasks and involves complex control flow dependencies, verification can take too much time or it may even be impossible. There are a number of different approaches to deal with this complexity. Reducing the size of the workflow, while preserving its essential properties with respect to a particular analysis problem, is one such approach. In this paper, we present a set of reduction rules for workflows with cancellation regions and OR-joins and demonstrate how they can be used to improve the efficiency of verification. Our results are presented in the context of the YAWL workflow language.

A brief history of haemotopoietic stem cell Ex vivo expansion

Haematopoiesis is the process by which a hierarchy of mature and progenitor blood cells are formed. These cell populations are all derived from multipotent haematopoietic stem cells (HSC), which reside in the bone marrow ‘niche’ of adult humans. Over the lifetime of a healthy individual, this HSC population replenishes between 1010-1011 blood cells on a daily basis. Dysregulation of this system can lead to a number of haematopoietic diseases, including aplastic anaemias and leukaemias, which result in, or require for disease resolution, bone marrow cell depletion. In 1956, E. Donnall Thomas demonstrated that haematopoiesis could be restored by transplanting bone marrow-derived cells from one man into his identical twin brother, who was suffering from advanced leukaemia. His success drew significant interest in academic research and medicine communities, and 12 years later, the first successful allogeneic transplant was performed. To this day, HSCs remain the most studied and characterised stem cell population. In fact, HSCs are the only stem cell population routinely utilised in the clinic. As such, HSCs function as a model system both for the biological investigation of stem cells, as well as for their clinical application. Herein, we briefly review HSC transplantation, strategies for the ex vivo cultivation of HSCs, recent clinical outcomes, and their impact on the future direction of HSC transplantation therapy.

Molecular structure of the phosphate mineral brazilianite NaAl3(PO4)2(OH)4 : a semi precious jewel

The phosphate mineral brazilianite NaAl3(PO4)2(OH)4 is a semi precious jewel. There are almost no minerals apart from brazilianite which are used in jewellery. Vibrational spectroscopy was used to characterize the mol. structure of brazilianite. Brazilianite is composed of chains of edge-sharing Al-O octahedra linked by P-O tetrahedra, with Na located in cavities of the framework. An intense sharp Raman band at 1019 cm-1 is attributed to the PO43- sym. stretching mode. Raman bands at 973 and 988 cm-1 are assigned to the stretching vibrations of the HOPO33- units. The IR spectra compliment the Raman spectra but show greater complexity. Multiple Raman bands are obsd. in the PO43- and HOPO33- bending region. This observation implies that both phosphate and hydrogen phosphate units are involved in the structure. Raman OH stretching vibrations are found at 3249, 3417 and 3472 cm-1. These peaks show that the OH units are not equiv. in the brazilianite structure. Vibrational spectroscopy is useful for increasing the knowledge of the mol. structure of brazilianite.

Facet-controlled Self-assembly of ZnO Nanocrystals by Non-Hydrolytic Aminolysis and their Photodegradation Activities

We report a method for controlling the exposed facets and hence the dimensionality and shape of ZnO nanocrystals using a non-hydrolytic aminolysis synthesis route. The effects of changes to reaction conditions on ZnO formation were investigated and possible self-assembly mechanisms proposed. The crystal facet growth and hence morphologies of the ZnO nanocrystals were controlled by varying reaction temperature and the reactant ratio. Four distinct ZnO nanocrystal types were produced (nanocones, nanobullets, nanorods and nanoplates). The relative photocatalytic activities of the exposed facets of these ZnO nanostructures were also examined, which showed the activities obviously depended on the reactivity of exposed crystal facets in the order: {1011}>>{0001}, {1010}.

Tracheobronchial and alveolar dose of submicrometer particles for different population age groups in Italy

Exposure to ultrafine particles (diameter less than 100 nm) is an important topic in epidemiological and toxicological studies. This study used the average particle number size distribution data obtained from our measurement survey in major micro-environments, together with the people activity pattern data obtained from the Italian Human Activity Pattern Survey to estimate the tracheobronchial and alveolar dose of submicrometer particles for different population age groups in Italy. We developed a numerical methodology based on Monte Carlo method, in order to estimate the best combination from a probabilistic point of view. More than 106 different cases were analyzed according to a purpose built sub-routine and our results showed that the daily alveolar particle number and surface area deposited for all of the age groups considered was equal to 1.5 x 1011 particles and 2.5 x 1015 m2, respectively, varying slightly for males and females living in Northern or Southern Italy. In terms of tracheobronchial deposition, the corresponding values for daily particle number and surface area for all age groups was equal to 6.5 x 1010 particles and 9.9 x 1014 m2, respectively. Overall, the highest contributions were found to come from indoor cooking (female), working time (male) and transportation (i.e. traffic derived particles) (children).