Approximate controllability and lack of controllability to zero of the heat equation with memory

In this paper we consider the heat equation with memory in a bounded region $\Omega \subset\mathbb{R}^d$, $d\geq 1$, in the case that the propagation speed of the signal is infinite (i.e. the Colemann-Gurtin model). The memory kernel is of class $C^1$. We examine its controllability properties both under the action of boundary controls or when the controls are distributed in a subregion of $\Omega$. We prove approximate controllability of the system and, in contrast with this, we prove the existence of initial conditions which cannot be steered to hit the target $0$ in a certain time $T$, of course when the memory kernel is not identically zero. In both the cases we derive our results from well known properties of the heat equation

Inverse design technique for cascades

A numerical technique to generate cascades is presented. The basic prescribed parameters are: inlet angle, exit pressure, and distribution of blade thickness and lift along a blade. Other sets of parameters are also discussed. The technique is based on the lambda scheme. The problem of stability of the computation as a function of the prescribed set of parameters and the treatment of boundary conditions is discussed. A one dimensional analysis to indicate a possible way for assuring stability for any two dimensional calculation is provided

New insight into the Pleistocene deposits of Monte delle Piche, Rome, and remarks on the biochronology of Hippopotamus (Mammalia, Hippopotamidae) and Stephanorhinus etruscus (Mammalia, Rhinocerotidae) in Italy

Several large mammal assemblages have been collected in the Roman basin since the XIX century, but they usually lack any stratigraphic datum or details about the fossiliferous localities. In this work, the stratigraphic provenance of large mammal remains discovered at Monte delle Piche (Rome) is investigated. The systematic revision of these specimens allows the recording of the presence of Hippopotamus sp., Stephanorhinus sp. and Stephanorhinus etruscus. On the basis of micropalaeontological analysis performed on sediment sampled from the studied specimens and considering the stratigraphy of the area, two fossiliferous levels are recognised at Monte delle Piche. The remain of the hippopotamus was collected in fluvial gravels and sand deposits, in which the presence of Cyprideis is also recorded. This deposit is chronologically related to the latest Early-early Middle Pleistocene. Hippopotamus was present in Italy and Western Europe from the latest Villafranchian to MIS 4/3. The mandible of S. etruscus was collected in marine deposits along with abundant foraminifera and ostracods, which correlate with the late Early Pleistocene. Stephanorhinus etruscus occurred in Western Europe at the beginning of the Villafranchian, and it was documented until the end of the Villafranchian in Italy and until the Early-Middle Pleistocene transition in the Iberian Peninsula

Boundary Controllability and Observability of a Viscoelastic String

In this paper we consider an integrodifferential system, which governs the vibration of a viscoelastic one-dimensional object. We assume that we can act on the system at the boundary and we prove that it is possible to control both the position and the velocity at every point of the body and at a certain time $T$, large enough. We shall prove this result using moment theory and we shall prove that the solution of this problem leads to identify a Riesz sequence which solves controllability and observability. So, the result as presented here are constructive and can lead to simple numerical algorithms

Scaling properties of a low-actuation pressure microfluidic valve

Using basic physical arguments, we present a design and method for the fabrication of microfluidic valves using multilayer soft lithography. These on-off valves have extremely low actuation pressures and can be used to fabricate active functions, such as pumps and mixers in integrated microfluidic chips. We characterized the performance of the valves by measuring both the actuation pressure and flow resistance over a wide range of design parameters, and compared them to both finite element simulations and alternative valve geometries

Controllability of a viscoelastic plate using one boundary control in displacement or bending

In this paper we consider a viscoelastic plate (linear viscoelasticity of the Maxwell-Boltzmann type) and we compare its controllability properties with the (known) controllability of a purely elastic plate (the control acts on the boundary displacement or bending). By combining operator and moment methods, we prove that the viscoelastic plate inherits the controllability properties of the purely elastic plate

A novel technique to close large perforation of sinus membrane

Maxillary sinus floor elevation is generally accepted as a regenerative procedure to facilitate dental implants placement in the posterior atrophic maxilla. Although the sinus lift procedure is relatively safe, some potential problems could be occur. The most prevalent intraoperative complication is perforation of sinus membrane, which can lead to graft infection and early failure. The Aim of this work. Is to present a new technique to repair large perforation of sinus membrane. This case report. Is focused on a 10 mm perforation of sinus membrane occurred during preparation of the sinus window. The obliteration of the perforation was obtained by means of suturing sinus membrane with a resorbable material to the bone directly lateral to the osteotomy site. Sinus augmentation procedure could complete and the insertion of a graft was permitted

The chromosome make-up of mouse embryonic stem cells is predictive of somatic and germ cell chimerism.

Mouse pluripotent embryonic stem (ES) cells, once reintroduced into a mouse blastocyst, can contribute to the formation of all tissues, including the germline, of an organism referred to as a chimaeric. However, the reasons why this contribution often appears erratic are poorly understood. We have tested the notion that the chromosome make-up may be important in contributing both to somatic cell chimaerism and to germ line transmission. We found that the percentage of chimaerism of ES cell-embryo chimaeras, the absolute number of chimaeras and the ratio of chimaeras to total pups born all correlate closely with the percentage of euploid metaphases in the ES cell clones injected into the murine blastocyst. The majority of the ES cell clones that we tested, which were obtained from different gene targeting knockout experiments and harboured 50 to 100% euploid metaphases, did transmit to the germline; in contrast, none of the ES cell clones with more than 50% of chromosomally abnormal metaphases transmitted to the germline. Euploid ES cell clones cultured in vitro for more than 20 passages rapidly became severely aneuploid, and again this correlated closely with the percentage of chimaerism and with the number of ES cell-embryo chimaeras obtained per number of blastocysts injected. At the same time, the ability of these clones to contribute to the germline was lost when the proportion of euploid cells dropped below 50%. This study suggests that aneuploidy, rather than 'loss of totipotency', in ES cells, is the major cause of failure in obtaining contributions to all tissues of the adult chimaera, including the germline. Because euploidy is predictive of germline transmission, karyotype analysis is crucial and time/cost saving in any gene-targeting experiment