Some Observations on the Embryology of Chronomus

All the eggs used in the following investigation were collected from a small pond in the eastern edge of the city of Indianola. The eggs were gathered from time to time at intervals of from one to three days, between June 20th and September 30th, 1902. They were found in abundance along the bank, in water from one to six inches deep. Usually they were attached to a piece of wood, or some plant growing in the edge of the water. Many were also found attached to the bottom. A few were found floating in the water, but as by far the greater number were attached, it is probable that those found floating had broken from their attachment, or by some accident had not been fastened

The Impact Of Climate On The Leaf Characteristics Of Genus Fraxinus

U radu su opisani hibridni sustavi obnovljivih izvora energije. Nakon fotonaponskog, vjetroturbinskog i toplinskog, prikazan je i napredni fotonaponsko/toplinski sustav za istovremenu proizvodnju električne i toplinske energije. Analizirana je potrošnja električne energije obiteljske kuće, te potrebe za energijom u pripremi potrošne tople vode. Također na lokaciji od interesa proučeni u meteorološki uvjeti o kojima ovisi proizvodnja energije sustava obnovljivih izvora (ozračenje, temperatura, brzina vjetra ). Korištenjem programskog paketa MATLAB napravljeni su sustavi koji računaju proizvodnju električne energije i toplinske energije. Također je napravljena ekonomska analiza, te je određeno jednostavno vrijeme povrata pojedine investicije.In this thesis renewable hybrid systems are described. After photovoltaic, thermal and wind system, a new photovoltaic/thermal system for simultaneous electrical and thermal energy production is also described. For a household of five electrical and thermal energy consumption was studied and used together with the meteorological data to create a MATLAB Simulink model of the system. The return of the investment was calculated for each system

Exploring Botnet Evolution via Multidimensional Models and Visualisation

A botnet is a program designed to perform a specific task using multiple computers connected in a network. In this paper we will focus on botnets being used to distribute malicious programs. In the real world, botnets have been shown to exhibit more aggressive and sophisticated behaviour than traditional malware. Botnets are used to infect computer networks and hence their success depends on the properties of the networks. We observe the behaviour of mathematical models used to describe botnets when botnet parameters are varied to understand if such variation is beneficial to their spread. We also introduce novel models for depicting botnet behaviour using master equations. These models, unlike previous ones, address nodes of distinct categories in a network as a sequence of probability distributions rather than a value at each time interval. We also contribute visualisations for these models. This paper is a substantial expansion of unpublished work the first author performed while on a Nuffield student research placement, with the second author the project supervisor

A preliminary quarantine analysis of a possible Mariner Venus 1972 mission

Spacecraft contamination preliminary quarantine analysis for possible 1972 Mariner Venus prob

Sample preparation for nanoanalytical electron microscopy using the FIB lift-out method and low energy ion milling

Thinning specimens to electron transparency for electron microscopy analysis can be done by conventional (2 - 4 kV) argon ion milling or focused ion beam (FIB) lift-out techniques. Both these methods tend to leave ''mottling'' visible on thin specimen areas, and this is believed to be surface damage caused by ion implantation and amorphisation. A low energy (250 - 500 V) Argon ion polish has been shown to greatly improve specimen quality for crystalline silicon samples. Here we investigate the preparation of technologically important materials for nanoanalysis using conventional and lift-out methods followed by a low energy polish in a GentleMill™ low energy ion mill. We use a low energy, low angle (6 - 8°) ion beam to remove the surface damage from previous processing steps. We assess this method for the preparation of technologically important materials, such as steel, silicon and GaAs. For these materials the ability to create specimens from specific sites, and to be able to image and analyse these specimens with the full resolution and sensitivity of the STEM, allows a significant increase of the power and flexibility of nanoanalytical electron microscopy

Texture, twinning and metastable "tetragonal" phase in ultrathin films of HfO₂ on a Si substrate

Thin HfO<sub>2</sub> films grown on the lightly oxidised surface of (100) Si wafers have been examined using dark-field transmission electron microscopy and selected area electron diffraction in plan view. The polycrystalline film has a grain size of the order of 100 nm and many of the grains show evidence of twinning on (110) and (001) planes. Diffraction studies showed that the film had a strong [110] out-of-plane texture, and that a tiny volume fraction of a metastable (possibly tetragonal) phase was retained. The reasons for the texture, twinning and the retention of the metastable phase are discussed

The Self: How Does it Relate to Locus of Control, Quality of Life and Adaptive Behaviour for People with Mild Intellectual Disabilities?

Research has found that when people with intellectual disabilities are moved from institutions into smaller community-based services, positive outcomes have been recorded. However, positive outcomes have not been inevitable. It is now recognised that mere placement in the community is not always sufficient. Individual characteristics of clients and the nature of services received in the community may be very significant to maintaining normalisation and social role valorisation. Areas that have consistently been found to have an impact on community-based living are the social competencies and affective functioning of people with intellectual disability. Given the recognised importance, it is surprising that these factors have not been the focus of more research in either the Australian or overseas context. This paper presents results from a study examining the social competence and affective functioning of people with intellectual disabilities. It describes the relations found for this population between multi-dimensional self- concept and locus of control, and quality of life

Conjugacy in Baumslag's group, generic case complexity, and division in power circuits

The conjugacy problem belongs to algorithmic group theory. It is the following question: given two words x, y over generators of a fixed group G, decide whether x and y are conjugated, i.e., whether there exists some z such that zxz^{-1} = y in G. The conjugacy problem is more difficult than the word problem, in general. We investigate the complexity of the conjugacy problem for two prominent groups: the Baumslag-Solitar group BS(1,2) and the Baumslag(-Gersten) group G(1,2). The conjugacy problem in BS(1,2) is TC^0-complete. To the best of our knowledge BS(1,2) is the first natural infinite non-commutative group where such a precise and low complexity is shown. The Baumslag group G(1,2) is an HNN-extension of BS(1,2). We show that the conjugacy problem is decidable (which has been known before); but our results go far beyond decidability. In particular, we are able to show that conjugacy in G(1,2) can be solved in polynomial time in a strongly generic setting. This means that essentially for all inputs conjugacy in G(1,2) can be decided efficiently. In contrast, we show that under a plausible assumption the average case complexity of the same problem is non-elementary. Moreover, we provide a lower bound for the conjugacy problem in G(1,2) by reducing the division problem in power circuits to the conjugacy problem in G(1,2). The complexity of the division problem in power circuits is an open and interesting problem in integer arithmetic.Comment: Section 5 added: We show that an HNN extension G = < H, b | bab^-1 = {\phi}(a), a \in A > has a non-amenable Schreier graph with respect to the base group H if and only if A \neq H \neq