Competing Interactions among Supramolecular Structures on Surfaces

A simple model was constructed to describe the polar ordering of non-centrosymmetric supramolecular aggregates formed by self assembling triblock rodcoil polymers. The aggregates are modeled as dipoles in a lattice with an Ising-like penalty associated with reversing the orientation of nearest neighbor dipoles. The choice of the potentials is based on experimental results and structural features of the supramolecular objects. For films of finite thickness, we find a periodic structure along an arbitrary direction perpendicular to the substrate normal, where the repeat unit is composed of two equal width domains with dipole up and dipole down configuration. When a short range interaction between the surface and the dipoles is included the balance between the up and down dipole domains is broken. Our results suggest that due to surface effects, films of finite thickness have a none zero macroscopic polarization, and that the polarization per unit volume appears to be a function of film thickness.Comment: 3 pages, 3 eps figure

Sejarah pengaruh pelita terhadap kehidupan masyarakat pedesaan daerah Sumatera Barat

Sampai saat ini telah dilaksanakan Pelita ketiga, dengan segala hasil yang telab dapat dirasakan manfaatnya. Telah banyak terjadi perubahan terbadap kebidupan masyarakat di daerab perkotaan, begitu juga di daerab pedesaan. Pengarub ini tidak banya dirasakan di daerah Indonesia lainnya, tetapi juga di Sumatera Barat. Tidak sedikit kebutuban bidup masyarakat Indonesia tergantung pada desa. Tetapi di lain pihak, mengingat laju transportasi yang membaik, maka desa pun tidak dapat pula menghindarkan diri dari pengaruh kota. Sadar akan pentingnya kedudukan dalam rangka pembangunan negara, maka pemerintah selalu meningkatkan perhatiannya ke desa. Bantuan pembangunan desa pada setiap Pelita semakin meningkat

Target-specific glioma therapy in an immunocompetent mouse model : meeting abstract

Objective: Establishment of an immunocompetent mouse model representing the typical progressive stages observed in malignant human gliomas for the in vivo evaluation of novel target-specific regimens. Methods: Isolated clones from tumours that arose spontaneously in GFAP-v-src transgenic mice were used to develop a transplantable brain tumour model in syngeneic B6C3F1 mice. STAT3 protein was knocked down by infection of tumour cells with replication-defective lentivirus encoding STAT3-siRNA. Apoptosis is designed to be induced by soluble recombinant TRAIL + chemical Bcl-2/Bcl-xL inhibitors. Results: Striatal implantation of 105 mouse tumour cells resulted in the robust development of microscopically (2 – 3 mm) infiltrating malignant gliomas. Immunohistochemically, the gliomas displayed the astroglial marker GFAP and the oncogenic form of STAT3 (Tyr-705-phosphorylated) which is found in many malignancies including gliomas. Phosphorylated STAT3 was particularly prominent in the nucleus but was also found at the plasma membrane of peripherally infiltrating glioma cells. To evaluate the role of STAT3 in tumour progression, we stably expressed siRNA against STAT3 in several murine glioma cell lines. The effect of STAT3 depletion on proliferation, invasion and survival will be first assessed in vitro and subsequently after transplantation in vivo. Upstream and downstream components of the STAT3 signalling pathway as well as possible non-specific side effects of STAT3-siRNA expression after lentiviral infection will be examined, too. Conclusions: Its high rate of engraftment, its similarity to the malignant glioma of origin, and its rapid locally invasive growth should make this murine model useful in testing novel therapies for malignant gliomas

Heart ventricular histology and microvasculature together with aortic histology and elastic lamellar structure: A comparison of a novel dual-purpose to a broiler chicken line

The use of dual-purpose chickens is a strategy to avoid killing one-day-old male chicks of egg laying lines. Lohmann Dual (LD) is a novel dual-purpose chicken line created by the crossbreeding of layer and broiler lines. However, many of the cardiovascular diseases of broilers are likely to be associated with intensive genetic selection for growth and feed conversion efficiency. This study aimed to compare the macroscopic and microscopic structure of the heart and the aorta of the LD chicken line with that of the broiler chicken line, Ross 308 (Ross) under typical husbandry conditions for meat production. Eighty, one-day-old male chicks of each line were housed for 5 weeks (Ross) and 9 weeks (LD). Six birds of each line were sampled weekly. Heart mass, thickness of ventricular walls, cardiomyocyte size and blood capillary density as well as aortic diameter and thickness, number of elastic lamellae and elastic fiber percentage in the aortic wall were determined. The growth patterns of the heart were the same in the two lines. Although LD chickens had a lower absolute heart mass than that of Ross chickens, the relative heart mass in both lines was similar. The cardiomyocytes of LD chickens were larger than those of Ross’s of the same body weight (BW), nevertheless both lines had similar thicknesses of their ventricular walls. The blood capillary density was greater in the LD heart than in that of the Ross heart. The aorta of LD chickens had proportionally; a greater aortic lumen radius, larger numbers of elastic lamellae and more elastic fibers than in Ross chickens. Our results suggest that the heart and aorta of the LD chickens have not been disadvantaged by their intensive genetic selection; furthermore, LD chickens have a better myocardial capillary supply and better aortic mechanical properties than those of Ross chickens

Analysis of the properties of a steering shaft used as a back-up for a steer-by-wire system during system failure

YesAn analysis is presented to determine the best selection criteria for the properties of a steering shaft to be used as a back-up apparatus for a steer-by-wire (SBW) system during system failure. The properties of interest are the steering-shaft stiffness and its damping coefficient. A mathematical model representing the failed state of an SBW system is derived, and a set of experiments to validate the model is presented. Once the model had been validated, further predictions of the car¿s handling behaviour for a range of steering-shaft properties and different road speeds were completed by simulations in MATLAB/Simulink. A minimum stiffness which did not cause the car to become unstable owing to overshoot was determined, and the minimum acceptable damping coefficient value was derived. It is concluded that the suggested stiffness and damping coefficient values increased the steering ratio, and the results of further investigations are presented, which confirm that the vehicle is safe to be driven in the event of SBW system failure if the recommended shaft properties are used

On the Effects of Droplet Loading on the Structure of Spray Jets

This paper uses advanced laser diagnostics to investigate the effects of droplet loading on the structure and mixing patterns of sprays in a non-reacting, turbulent jet. A nozzle designed at University of Sydney with the objective of studying spray flames has been used for producing a two phase flow in a co-flowing air stream with well defined boundary conditions. Varying the quantity of liquid injective will vary the number density of the droplets in the flow. The co-flowing air stream is seeded with a fixed concentration of nitric oxide, NO which will act as a conserved scalar. Laser induced fluorescence of NO is exploited to provide a direct quantitative measure of the mixture fraction. Radial profiles of the mean and the rms of mixture fraction has been collected at various axial positions in jets with different spray loadings. It is found that mixture fraction profiles are different from those measured in turbulent gaseous jets and increasing the droplet loading increases the mixture fraction of the jet due to evaporating droplets

Design concepts and analysis of a semi-active steering system for a passenger car

YesThe fundamentals and preliminary analyses of an innovative future technology referred to as `semi-active steering' (SAS) are presented in this article. The proposed steering system configuration is similar to a conventional electrical power-assisted steering with the replacement of the rigid steering shaft with a low stiffness resilient shaft (LSRS), the presence of which allows `active control¿ to be performed on vehicles similar to the concept of full steer-by-wire (SBW). But, unlike SBW, the LSRS is an integral part of the system characteristics. The advantages of the semi-active system in comparison with SBWand other conventional systems are demonstrated. A mathematical model to predict the mechanical properties of the LSRS has been developed, and experiments were conducted on a medium-sized car fitted with an LSRS to verify that vehicle stability and drivability can be ensured in the event of active system failure. The results have indicated that the vehicle was stable and safe to be driven at low speeds, and is predicted to be driveable and safe at higher speeds. It is concluded that an SAS system of this type has the potential to improve the safety of SBW systems