Resonant Transport in Nb/GaAs/AlGaAs/GaAs Microstructures

Resonant transport in a hybrid semiconductor-superconductor microstructure grown by MBE on GaAs is presented. This structure experimentally realizes the prototype system originally proposed by de Gennes and Saint-James in 1963 in \emph{all}-metal structures. A low temperature single peak superimposed to the characteristic Andreev-dominated subgap conductance represents the mark of such resonant behavior. Random matrix theory of quantum transport was employed in order to analyze the observed magnetotransport properties and ballistic effects were included by directly solving the Bogoliubov-de Gennes equations.Comment: 7 pages REVTeX, 4 figures, to be published by World Scientific in Proceedings of International Symposium on Mesoscopic Superconductivity and Spintronics (NTT R&D Center Atsugi, Japan, March 2002

Smoothing semi-smooth stable Godeaux surfaces

We show that all the semi-smooth stable complex Godeaux surfaces, classified in [M. Franciosi, R. Pardini and S. Rollenske, Ark. Mat. 56 (2018), no. 2, 299–317], are smoothable and that the moduli stack is smooth of the expected dimension 8 at the corresponding points

I-surfaces with one T-singularity

We classify normal stable surfaces with KX2=1, pg= 2 and q= 0 with a unique singular point which is a non-canonical T-singularity, thus exhibiting two divisors in the main component and a new irreducible component of the moduli space of stable surfaces M¯ 1 , 3

Changing the approach to sustainable constructions: An adaptive mix-design calibration process for earth composite materials

One major drawback of excavation earth-based composite construction materials is the variability in excavation earth characteristics from site to site. This variability can affect certain physical properties, and, in turn, the design models used to create a structure. To solve this problem, a methodology has been developed to predict the physical properties of earth-based composites for any mix-design variation, which enables a robust structural design process. This new methodology has been tested for Shot-earth, a new class of earth-based composite material made using high rates of excavation earth, aggregates, and a low rate of stabilization if needed. Shot-earth is placed using a high-speed dry-mix process. The methodology was tested by preparing small, inexpensive specimens through a process that simulates the dry-process used to fabricate Shot-earth in the field. An adaptive technique, used in conjunction with the experimental methodology, allows for the identification of the variant of possible Shot-earth mix-designs that provides optimal physical properties for a specific project. This technique is potentially applicable to any type of earth-based composite. The proposed methodology’s reliability enables a fast and cost-effective detailing of Shot-earth constructions

Structural design of reinforced earthcrete (ReC) beams

This paper presents the results of an extensive experimental campaign aimed at evaluating the feasibility of using steel-reinforced earthen materials for load-bearing structural applications, with a focus on a new category termed "shot-earth". Addressing excavated soil, a major source of construction waste, shot-earth demonstrates remarkable properties, such as notable green strength and reduced water sensitivity. The experimental program includes four-point bending tests on steel-reinforced shot-earth beams, along with pull-out tests to assess the adherence between ribbed steel bars and shot-earth. A flexural design approach, traditionally suited for reinforced concrete, is presented and validated to establish a reliable model for reinforced shot-earth elements in bending state. These findings suggest that leveraging existing models for reinforced concrete can overcome some traditional challenges associated with earth-based constructions, promoting them as a viable and ecological alternative to conventional construction materials