Alkali treatment and its effect on tribological properties of naturally woven coconut sheath polyester composite

In the recent years natural fibres have drawn great interest for its bio-degradability, low cost and its availability in nature. Among different types of natural fibres, naturally woven coconut sheath fibres are one of the recently explored alternatives for synthetic fibres. These fibres are generally treated with alkali for enhancing mechanical properties and reinforcing characteristics. Tribological applications like gears, cams, bearings, etc. can be benefited from such composites. In most cases chemical treatment are done favouring the structural properties however, their influence on tribological properties are rather not considered. In the current research, hybrid composites (polyester resin with naturally woven coconut sheath (N) and glass fibres (G)) were tested against hardened steel counterface in a pin on disc configuration. Tests were performed at 40 N normal force and 3.5 m/s sliding velocity. From the results all hybrid combinations except (NNN) shows degrading wear properties with the alkaline treatment. The friction properties are modified by having low friction coefficients for all combinations except NGN and GGG hybrids. From the observed SEM images the surface morphology of NNN hybrid significantly differs from the rest of the combinations in both treated and untreated specimens. The partial removal of individual phase (resin) prevails in untreated specimen for which the fibres are highly visible. However, such phenomenon is not dominant in the alkali treated material showing better reinforcing behaviour complimenting low friction properties. The alkali treated specimen has reduced fibre size comparing the untreated specimen which results in low wear resistance. Compromise between friction and wear properties between each other the untreated fibres are best suited for tribological applications. Furthermore, investigations on treatment process and other treatments might have some influence in tribological behaviour

Physiologische Bewertung aktiver und passiver Lichtsysteme im Automobil

Der Mensch definiert die funktionalen Anforderungen an Lichtsysteme im Automobil. So stellt sich mit der Integration neuer Konzepte im Fahrzeug vor allem die Frage nach deren Einfluss auf die Wahrnehmungsleistung des Fahrers. Daher bildet die physiologisch-psychologische Bewertung von Lichtfunktionen ein wichtiges Glied in der Entwicklungskette lichttechnischer Komponenten. Im Rahmen der vorliegenden Arbeit werden ausgewählte Systeme im In- und Exterieurbereich psychophysikalisch analysiert

2-Amino­pyridinium 4-hydroxy­benzoate

In the title compound, C5H7N2 +·C7H5O3 −, the carboxyl­ate mean plane of the 4-hydroxy­benzoate anion is twisted by 8.78 (5)° from the attached ring. The cations and anions are linked via O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds, forming a three-dimensional network. In addition, π–π inter­actions involving the benzene and pyridinium rings, with centroid–centroid distances of 3.5500 (6) and 3.6594 (6) Å, are observed

Bis(2-amino­pyridine-κN 1)silver(I) nitrate

The asymmetric unit of the title compound, [Ag(C5H6N2)2]NO3, consists of one and a half each of both cations and anions, the other halves being generated by crystallographic inversion centres. One of the AgI atoms lies on an inversion center and one of the nitrate ions is disordered across an inversion center. Each AgI atom is bicoordinated in a linear geometry by two N atoms from two 2-amino­pyridine ligands. In the crystal structure, the cations and anions are linked into a two-dimensional network parallel to (001) by N—H⋯O and C—H⋯O hydrogen bonds

Czech nuclear law

Tématem diplomové práce je české atomové právo. Atomové právo je soubor právních norem, které upravují způsob a podmínky využívání jaderné energie a ionizujícího záření, systém ochrany osob a životního prostředí před nežádoucími účinky ionizujícího záření, povinnosti v případech vzniku radiačních nehod, podmínky nakládání s radioaktivními odpady a výkon státní správy a dozoru při využívání jaderné energie a ionizujícího záření. Po krátkém pohledu do historie využívání jaderné energie a ionizujícího záření následují dvě kapitoly věnované mezinárodnímu a unijnímu atomovému právu. V těchto kapitolách jsou vymezeny cíle a obsah mezinárodní a unijní spolupráce v oblasti mírového využívání jaderné energie a ionizujícího záření. Ostatní kapitoly jsou věnovány českému atomovému právu. Jsou vymezeny ústavní základy českého atomového práva, předmět právní úpravy atomového zákona a zásady, na kterých je české atomové právo postaveno. Následuje charakteristika pravomocí orgánů státní správy působících v oblasti mírového využívání jaderné energie a ionizujícího záření. Pozornost je dále věnována klasifikaci zdrojů ionizujícího záření a charakteristice nástrojů, které právní úprava používá k ochraně životního prostředí před riziky souvisejícími s využíváním těchto zdrojů. Opomenuta nezůstala ani právní úprava...The topic of this diploma thesis is Czech Nuclear Law. The nuclear law is a set of legal norms concerned with the ways and conditions of usage of nuclear energy and ionising radiation, the systems used to protect people and the environment against the damaging effects of ionising radiation, protocols to be followed in the case of accidents, radioactive waste disposal as well as the role of the state administration in supervising usage of nuclear energy and ionising radiation. A short historical review of the usage of nuclear energy and ionising radiation is followed by 2 chapters dedicated to international and EU nuclear law. The aims and content of international and EU collaboration concerning non-military usage of nuclear energy and ionising radiation are defined in these chapters. The other chapters of this thesis are concerned with Czech Nuclear Law. The constitutional foundation of this Law is described as well as nuclear law as a legal subject and the rules forming the base of Czech Nuclear Law. The following section deals with the power characteristics of the individual state authorities in the field of non-military usage of nuclear energy. Attention is paid to the classification of ionising radiation sources and characteristics of the tools used by the legal norm for environmental...Department of Environmental LawKatedra práva životního prostředíFaculty of LawPrávnická fakult

Tetra­aqua­bis[3-(2-pyridylsulfan­yl)propionato N-oxide]nickel(II)

In the centrosymmetric title compound, [Ni(C8H8NO3S)2(H2O)4], the NiII ion, which lies on an inversion centre, is six coordinated by four water mol­ecules and two propionate O atoms from two 2-pyridylsulfanylpropionate N-oxide ligands, forming a slightly distorted octa­hedral geometry. An intra­molecular O—H⋯O hydrogen bond stabilizes the mol­ecular conformation. The crystal packing is consolidated by inter­molecular O—H⋯O and C—H⋯O hydrogen bonding

catena-Poly[[aqua­sodium(I)]-μ-[2,2′-(disulfanedi­yl)bis­(pyridine N-oxide)]-μ-(pyridine-2-thiol­ato 1-oxide)]

There are two monomeric units in the asymmetric unit of the polymeric title compound, [Na(C5H4NOS)(C10H8N2O2S2)(H2O)]n. The NaI ions are six coordinated by four O atoms, one S atom and one water mol­ecule, forming a slightly distorted octa­hedral geometry. An intra­molecular O—H⋯O hydrogen bond stabilizes the conformation of the mol­ecule. The crystal packing is consolidated by inter­molecular O—H⋯O, O—H⋯N and O—H⋯S hydrogen bonds, π–π inter­actions [with centroid–centroid distances of 3.587 (2) Å] together with weak C—H⋯π inter­actions. The mol­ecules are linked into polymeric chains along the b-axis direction

2-(Benzyl­sulfan­yl)pyridine N-oxide

In the title compound, C12H11NOS, the dihedral angle between the oxopyridinium and phenyl rings is 58.40 (1)°. The crystal structure is stabilized by C—H⋯O hydrogen bonds, π–π stacking inter­actions involving the pyridinium rings [centroid–centroid distance = 3.6891 (9) Å] and C—H⋯π inter­actions

2-(Mesitylmethyl­sulfan­yl)pyridine N-oxide–18-crown-6 (2/1)

In the title compound, 2C15H17NOS·C12H24O6, the asymmetric unit consists of one N-oxide derivative and one-half of the 18-crown-6 ether, which lies on an inversion centre. In the crown ether, the O—C—C—O torsion angles indicate a gauche conformation of the ethyl­eneoxy units, while the C—O—C—C torsion angles indicate planarity of these segments. In the N-oxide unit, the dihedral angle between the pyridine and benzene rings is 85.88 (12)°. The crystal packing is stabilized by weak C—H⋯O hydrogen bonds and C—H⋯π inter­actions