How Yield Process Misspecification Affects the Solution of Disassemble-to-order Problems

Random yields from production are often present in manufacturing systems and there are several ways that this can be modeled. In disassembly planning, the yield uncertainty in harvesting parts from cores can be modeled as either stochastically proportional or binomial, two of these alternatives. A statistical analysis of data from engine remanufacturing of a major car producer fails to provide conclusive evidence on which kind of yield randomness might prevail. In order to gain insight into the importance of this yield assumption, the impact of possible yield misspecification on the solution of the disassemble-to-order problem is investigated. Our results show that the penalty for misspecifying the yield method can be substantial, and provide insight on when the penalty would likely be problematic. The results also indicate that in the absence of conclusive information on which alternative should be chosen, presuming binomial yields generally leads to lower cost penalties and therefore preferable results

Natural zeolites and white wines from Campania region (Southern Italy): a new contribution for solving some oenological problems

The purpose of this research is to provide a new mixture of Campanian zeolitized tuffs for solving two specific problems in the production of white wines: the protein and tartaric stability. In fact, a very frequent cause of turbidity and formation of organic deposits in white wines is the occurrence of thermolabile and thermostable proteins colloidal suspensions which precipitate in time, especially in summertime and during the storage and transport. Normally, to mitigate this risk wine producers use organic and inorganic stabilizers and clarifiers. The best known treatment, recognized also by the International Organisation of Vine and Wine (OIV) foresees the use of bentonite with a montmorillonite content not lower than 80%. The present paper aims at evaluating the use of two high zeolite grade Italian volcanoclastites such as the Neapolitan Yellow Tuff (NYT) and the Yellow Facies of the Campanian Ignimbrite (YFCI), in the treatment of three peculiar white wines of the Campanian region (Southern Italy): Falanghina, Fiano di Avellino and Greco di Tufo. Granulates were produced starting from tuff blocks as provided by quarries. Some grain size fractions have been prepared to investigate the zeolite content (phillipsite + chabazite + analcime) by X-ray diffraction (XRD). A 2-5 mm grain size fraction was chosen for NYT and a 5-10 mm for YFCI. Three Campanian monocultivar white wines were used for the test: the Falanghina 2006 vintage, the Fiano di Avellino DOCG 2007 vintage, and the Greco di Tufo DOCG 2008 vintage. 48 samples with mixture of the zeolitized tuffs, 1 sample with mixture of a synthetic zeolite A and 1 sample with mixture of a commercial sodium activated bentonite were prepared. ICP-OES analysis for the determination of ECEC, Ion Chromatography (IC) analyses for the determination of some major cations and Turbidimetric tests for the definition of the protein stabilization process before and after treatments were also carried out. It was evidenced that high zeolitized tuff/wine ratios enable the protein stabilization whereas a significant decrease of potassium ion after the treatment with a zeolite-rich powder improves the tartaric stability, a serious problem in all the wine productions. The results of these tests refer to a laboratory scale research. A transfer of the experiment to a pilot plant scale is in progress

Neuronal nitric oxide synthase (NOS I) in the buffalo epididymis

The localization of neuronal nitric oxide (NOS I) in the buffalo epididymis have been investigated by nicotinamide adenite dinucleotide phosphatase-diaphorase (NADPH-d) histochemichemistry to the light microscope (LM) and NOS immunoistochemistry to the scanning electron microscope (SEM), respectively. Histochemistry: examination of epididymis specimens revealed an intense NADPH-d staining in the basal cell epithelium and endothelium cells of blood vessel. The NADPH diaphorase staining was diffuse and granular only along the caput epididymal epithelium. NADPH diaphorase staining was less intense or absent in the corpus and in the cauda of epididymis. Dense NADPH diaphorase is labeling in the endothelium of blood vessels along the whole buffalo epididymis. Immunoistochemistry: intense NOS I immunoreactivity was detected in the caput epididymis specimen by immuno-SEM. The basal epithelium showed intense and wide-spread immunoreactivity. In the corpus and in the cauda of the epididymis not observed NOS I immunoreactivity. The specific localization of NOS I in buffalo epididymis suggest that nitric oxide may be involved to explain epididymal function: maturation and storage

Verbi locativi in italiano come varianti di verbi supporto

In questo articolo discuteremo la nozione di "carrier verbs" (secondo la definizione del linguista americano Zellig Harris) o di "light verbs" (come denominata all'inizio del XX secolo da Otto Jespersen). La nostra cornice teorica è rappresentata dal lessico-grammatica di Maurice Gross, una teoria iniziata negli anni settanta a partire dalla sintassi del francese sulle basi matematiche già individuate per la lingua inglese da Zellig Harris. In particolare, discuteremo di come alcuni verbi locativi dell'italiano possano essere usati come verbi supporto (secondo la definizione data da Gross dei "light verbs" harrisiani) e assumano il ruolo sintattico una volta attribuito dai grammatici greci e latini alla copula esse.En aquest article discutirem la noció de "carrier verbs" (segons la definició del lingüista americà Zellig Harris) o de "light verbs" (segons la denominació que Otto Jespersen n'havia donat a principi del segle XX). El nostre marc teòric de referència és el lèxic-gramàtica de Maurice Gross, una teoria començada els anys setanta a partir de la sintaxi del francès en les bases matemàtiques ja individuades per a la llengua anglesa per Zelling Harris. Concretament, tractarem de com alguns verbs locatius de l'italià es poden emprar com a verbs de suport (tal com Gross va definir els "light verbs" harrisians) i de com assumeixen el paper sintàctic que els gramàtics grecs i llatins atribuïen a la còpula esse.In this article we aim at discussing the notion of carrier verbs (according to the definition provided by the American linguist Zellig Harris) or of light verbs (as defined at the beginning of the twentieth century by Otto Jespersen). Our theoretical framework is represented by Maurice Gross' lexicon-grammar, a theory developed during the seventies on the French syntax and directly inspired by Zellig Harris' mathematical grammar of English. Particularly, we are going to discuss of how some Italian locative verbs can be used as support verbs (according to the definition which Maurice Gross has given of the harrisian light verbs) and can play the syntactic role traditionally given to the copula esse by the Greek and Latin grammarians

The Current Profile of Aquatic Rehabilitation, Fitness, and Training Practitioners

Aquatic rehabilitation, fitness, and training practitioners are perceived as competent, knowledgeable, certified specialists who use a comprehensive therapeutic approach in combination with aquatic techniques to aid in the rehabilitation of various conditions. These specialists, however, have diverse educational backgrounds that include content in movement, knowledge of chronic and acute disabling conditions, diseases, and aquatic techniques. In the past two decades, aquatic therapy has become a diverse multidisciplinary field. Each aquatic practitioner's role is individually defined, and each individual may hold a different job description, work with different populations, and possess different preparation and training.   A growing body of literature tends to support the efficacy and benefits of aquatic rehabilitation, fitness, and training in general, yet within the aquatic field it remains unclear who actually provides these aquatic rehabilitation, fitness, and training services (Norton & Jamison, 2000). The purpose of this study was to examine aquatic practitioners currently providing aquatic rehabilitation, fitness, and training services from two of the leading aquatic organizations, Aquatic Resource Network (ARN) and Aquatic Therapy & Rehab Institute (ATRI). The study was designed to help identify and describe the individuals providing aquatic rehabilitation, fitness, and training services. Five research questions were posed to examine relationships between the professional profile of respondents of the two aquatic organizations and the types of credentialing, settings, and population groups, and services provided.  A descriptive questionnaire consisting of 26 questions was designed and is divided into three sections: (a) demographic, (b) facility, and (c) aquatic therapy continuing professional development information. Each section focused on the establishment of a profile of aquatic rehabilitation, fitness, and training practitioners of the targeted organizations. The questionnaire was validated for content validity via a jury of experts with knowledge in survey design and aquatics. In order to achieve maximum survey response the principle investigator followed Dillman's (2000) Tailored Design Method (TDM).  This study yielded 180 usable surveys, with comparable responses from both aquatic organization memberships. The study sample consisted of 16.1% (n = 29) Aquatic Resource Network (ARN) respondents, 21.6% (n = 39) Aquatic Therapy and Rehab Institute (ATRI) respondents, 21.6% (n = 39) respondents belonging to both organizations, and 29.4% (n = 53) respondents belonging to neither organization.   Results reflect a diverse field of practitioners and a general lack of consistency in educational background, aquatic training and certifications, and populations served. Implications for consistency and credentialing are addressed.  M.S

conventional orthogonal cutting machining on unidirectional fibre reinforced plastics

Abstract The results of orthogonal cutting tests on unidirectional carbon and glass fibre reinforced plastics are presented. The specimens were under shape of rectangular plates, circular disks and cylinders with different fibre architectures and a milling machine, a lathe machine and a five-axis high-speed vertical machining centre, were used for the experimental tests. The cutting speed was varied. During the tests, performed at low cutting speed, avoiding thermal effects, and high speed, to investigate about the effect of the cutting velocity on the cut quality, the fibre orientation respect to the cutting direction, the tool rake angle and the depth of cut were varied to investigate their influence on the phenomenon. A high speed steel tool in different geometries, was used. The mechanisms of chip formation and the cutting quality were investigated. A tentative to correlate the mechanisms of chip formation and cutting forces signals was done. Since the anisotropy, the mechanisms of chip formation consists of different failure modes occurring simultaneously and their identification, on the basis of the cutting force evolution, is very complex. Only in particular conditions, the features of cutting forces allow a precise identification of the chip development and detachment. The results indicated that the fibre orientation respect to the cutting direction determines the mechanisms of chip formation and influences the cutting quality. It was noted that for fibre orientation higher than 60°, the quality of the surface was revealed unacceptable. These conclusions were obtained independently of the particular shape of specimen tested and of the speed adopted

Dynamic-Mechanical Behaviour of Bio-composites☆

Abstract PLA-hemp bio-composites with different reinforcement content were manufactured by compression moulding process. Both flexural and impact properties were investigated and compared to the unreinforced polymer. In addition, also the creep behaviour adopting the Arrhenius theory was determined, in order to better understand the industrial application limits of PLA reinforced by natural fibres. For this purpose, DMA tests were carried out, in order to evaluate the activation energy and to apply the Time-Temperature Superposition model to the compliance curves obtained by short-time creep tests

Turbulent flame shape switching at conditions relevant for gas turbines

Abstract A numerical investigation is conducted in this work to shed light on the reasons leading to different flame configurations in gas turbine combustion chambers of aeronautical interest. Large eddy simulations (LES) with a flamelet-based combustion closure are employed for this purpose to simulate the DLR-AT Big Optical Single Sector (BOSS) rig fitted with a Rolls-Royce developmental lean burn injector. The reacting flow field downstream this injector is sensitive to the intricate turbulent-combustion interaction and exhibits two different configurations: (i) a penetrating central jet leading to an M-shape lifted flame; or (ii) a diverging jet leading to a V-shaped flame. First, the LES results are validated using available BOSS rig measurements, and comparisons show that the numerical approach used is consistent and works well. The turbulent-combustion interaction model terms and parameters are then varied systematically to assess the flame behavior. The influences observed are discussed in the paper from physical and modelling perspectives to develop physical understanding on the flame behavior in practical combustors for both scientific and design purposes.Clean Sky 2 Joint Undertaking under the European Union’s Horizon 2020 research and innovation programme (grant agreement No 686332

Large Eddy Simulation of a dual swirl gas turbine combustor: Flame/flow structures and stabilisation under thermoacoustically stable and unstable conditions

A laboratory gas turbine model combustor with dual-swirler configuration is in- vestigated using Large Eddy Simulation (LES) with a flamelet subgrid combus- tion model. Two partially premixed methane/air flames with different equivalence ratio and thermal power are simulated: one stably burning with an elongated V- shape and another undergoing pronounced thermoacoustic oscillations exhibiting a flat shape. Additionally, both flames feature a hydrodynamic instability in the form of a precessing vortex core (PVC). Detailed comparisons between experi- mental and LES results show that the different flow and reaction zone structures in these two flames are reproduced well. The various flow dynamics resulting from the PVC and thermoacoustic oscillations are also captured accurately in the simulation. Further analyses on the lifted swirl flame stabilisation using phase averaged statistics at the PVC frequencies reveal that the PVC-induced stagnation points provide an anchoring mechanism for both the stable and unstable flames, although in the latter case large self-excited pressure oscillations are present. It is found that the PVC is significantly influenced by these oscillations, being axially stretched and compressed at high and low pressures, respectively. However, the formation of flame leading edge due to the PVC is robust during these unstable processes and the azimuthal movement of the leading point is found to be strongly correlated with the rotation of the PVC in both flames, further confirming the vital role of the PVC in the stabilisation process of these lifted swirl flames

The influence of national culture on business students\u27 career attitudes - An analysis of eight countries | Der einfluss nationaler kulturen auf die karriere-einstellungen von wirtschaftsstudenten - Eine analyse aus acht landern

Despite the fact that career attitudes and their influence on career outcomes is widely researched in the field of occupations and careers, little is known about the influence of cultural norms and values on career attitudes. We propose that national cultural dimensions influence students\u27 career planning, career adaptability, career optimism, and career-related knowledge. We test these relations using an eight country sample with more than 1,800 students. The results show that national culture has significant effect on all four career attitudes and in particular on career planning and career optimism. We discuss theoretical and practical implications and provide future research directions