Single-Inclusive Jet Production in Polarized pp Collisions at O(alpha_s^3)

We present a next-to-leading order QCD calculation for single-inclusive high-p_T jet production in longitudinally polarized pp collisions within the ``small-cone'' approximation. The fully analytical expressions obtained for the underlying partonic hard-scattering cross sections greatly facilitate the analysis of upcoming BNL-RHIC data on the double-spin asymmetry A_{LL}^{jet} for this process in terms of the unknown polarization of gluons in the nucleon. We simultaneously rederive the corresponding QCD corrections to unpolarized scattering and confirm the results existing in the literature. We also numerically compare to results obtained with Monte-Carlo methods and assess the range of validity of the ``small-cone'' approximation for the kinematics relevant at BNL-RHIC.Comment: 23 pages, 8 eps-figure

Processability and Microstructural Evolution of W360 Hot Work Tool Steel by Directed Energy Deposition

Laser directed energy deposition (L-DED) was used to produce samples of the newly patented W360 hot work tool steel by Böhler. The process parameters were optimized to obtain nearly fully dense samples through the production and analysis of single deposited tracks and single layers. Subsequently, bulk samples underwent a hardening heat treatment, consisting of austenitizing, air quenching, and tempering. The samples were analysed in the as-built condition (AB), after quenching (Q) and following tempering cycles (HT) to observe the microstructural evolution. The microstructure was investigated using optical and scanning electron microscopes, energy dispersive X-ray analysis, and X-ray diffraction analysis. Furthermore, the microstructural evolution was analysed with differential scanning calorimetry, while the mechanical response was evaluated through microhardness test. It was found that the AB samples exhibited a dendritic-cellular microstructure with tempered martensite laths. The thermal history of the AB samples was completely modified by the austenitizing treatment followed by quenching, resulting in a fully martensitic Q sample that did not display the typical dendritic-cellular microstructure of the L-DED process. The completion of the heat treatment with tempering cycles revealed the presence of Mo-rich carbides dispersed in a martensitic matrix. The HT samples exhibited a mean microhardness of 634 HV, remaining constant along the entire building direction from the substrate to the last deposited layer, indicating a homogeneous microstructure. This high value, similar to other hot work tool steels such as H13, makes W360 a very promising candidate for tool build and repair purposes

Digital Machines, Space, And Time: Towards A Behavioral Perspective Of Flexible Manufacturing

Recently, the diffusion of digital machines has further enhanced firms’ manufacturing flexibility, but also opened questions on potential challenges and implications in the production process. To respond to these timely issues, we adopt a behavioral perspective and comparatively explore how four different types of digital machines—characterized by increasing degrees of manufacturing flexibility—affect the perception and use of space and time for routines within the production plant. We qualitatively observe and compare 45 digital manufacturing machines, sampled across 14 firms in the British and Italian motorsport industry. A model emerges where four key mechanisms reshape the ‘space-machine’ and ‘time-machine’ routines. Such mechanisms mediate the relationship between manufacturing flexibility and firm performance. Further, we show how increasing digitalization in the manufacturing process enhances the establishment of new routines as flexible machines get introduced in the production. Finally, we discuss the theoretical and practical implications related to fostering a behavioral perspective in innovation and operations management studies

Jets and produced particles in pp collisions from SPS to RHIC energies for nuclear applications

Higher-order pQCD corrections play an important role in the reproduction of data at high transverse momenta in the energy range 20 GeV $\leq \sqrt{s} \leq 200$ GeV. Recent calculations of photon and pion production in $pp$ collisions yield detailed information on the next-to-leading order contributions. However, the application of these results in proton-nucleus and nucleus-nucleus collisions is not straightforward. The study of nuclear effects requires a simplified understanding of the output of these computations. Here we summarize our analysis of recent calculations, aimed at handling the NLO results by introducing process and energy-dependent $K$ factors.Comment: 4 pages with 5 eps figures include

Enzyme activities in aged conidia of N. crassa

Enzyme activities in aged conidia of N. crass

Failure mode analysis on compression of lattice structures with internal cooling channels produced by laser powder bed fusion

Conformal cooling coils have been developed during the last decades through the use of additive manufacturing (AM) technologies. The main goal of this study was to analyze how the presence of an internal channel that could act as a conformal cooling coil could affect compressive strength and quasi-elastic gradient of AlSi10Mg lattice structures produced by laser powder bed fusion (LPBF). Three different configurations of samples were tested in compression at 25 °C and 200 °C. The reference structures were body centered cubic (BBC) in the core of the samples with vertical struts along Z (BCCZ) lattices in the outer perimeter, labelled as NC samples. The main novelty consisted in inserting a straight elliptical channel and a 45° elliptical channel inside the BCCZ lattice structures, labelled as SC and 45C samples respectively. All the samples were then tested in as-built (AB) condition, and after two post process heat treatments, commonly used for AlSi10Mg LPBF industrial components, a stress relieving (SR) and a T6 treatment. NC lattice structures AB exhibited an overall fragile fracture and therefore the SC and 45C configuration samples were tested only after thermal treatments. The test at 25 °C showed that all types of samples were characterized by negligible variations in their quasi-elastic gradients and yield strength. On the contrary, the general trend of stress-strain curves was influenced by the presence of the channel and its position. The test at 200 °C showed that NC, SC and 45C samples after SR and T6 treatments exhibited a metal-foam like deformation