Combustion Modeling Approach for the Optimization of a Temperature Controlled Reactivity Compression Ignition Engine Fueled with Iso-Octane

In this study, an innovative Low Temperature Combustion (LTC) system named Temperature Controlled Reactivity Compression Ignition (TCRCI) is presented, and a numerical optimization of the hardware and the operating parameters is proposed. The studied combustion system aims to reduce the complexity of the Reaction Controlled Compression Ignition engine (RCCI), replacing the direct injection of high reactivity fuel with a heated injection of low reactivity fuel. The combustion system at the actual state of development is presented, and its characteristics are discussed. Hence, it is clear that the performances are highly limited by the actual diesel-derived hardware, and a dedicated model must be designed to progress in the development of this technology. A Computational Fluid Dynamics (CFD) model suitable for the simulation of this type of combustion is proposed, and it is validated with the available experimental operating conditions. The Particle Swarm Optimization (PSO) algorithm was integrated with the Computational Fluid Dynamic (CFD) software to optimize the engine combustion system by means of computational simulation. The operating condition considered has a relatively high load with a fixed fuel mass and compression ratio. The parameters to optimize are the piston bowl geometry, injection parameters and the boosting pressure. The achieved system configuration is characterized by a wider piston bowl and injection angle, and it is able to increase the net efficiency of 3% and to significantly reduce CO emissions from 0.407 to 0.136 mg

Non-Abelian Vortices without Dynamical Abelianization

Vortices carrying truly non-Abelian flux moduli, which do not dynamically reduce to Abelian vortices, are found in the context of softly-broken ${\cal N}=2$ supersymmetric chromodynamics (SQCD). By tuning the bare quark masses appropriately we identify the vacuum in which the underlying SU(N) gauge group is partially broken to SU(n) \times SU(r) \times U(1)/{\mathbbm Z}_{K}, where $K$ is the least common multiple of $(n, r)$, and with $N_{f}^{su(n)}=n$ and $N_{f}^{su(r)}=r$ flavors of light quark multiplets. At much lower energies the gauge group is broken completely by the squark VEVs, and vortices develop which carry non-Abelian flux moduli $CP^{n-1}\times CP^{r-1}$. For $n>r$ we argue that the SU(n) fluctuations become strongly coupled and Abelianize, while leaving weakly fluctuating $SU(r)$ flux moduli. This allows us to recognize the semi-classical origin of the light non-Abelian monopoles found earlier in the fully quantum-mechanical treatment of 4D SQCD.Comment: 22 pages, 4 figures, One section (Section 2) added, and an extended discussion added in Section

Spin imbalance effect on Larkin-Ovchinnikov-Fulde-Ferrel state

We study spin imbalance effects on the Larkin-Ovchinikov-Fulde-Ferrel (LOFF) state relevant for superconductors under a strong magnetic field and spin polarized ultracold Fermi gas. We obtain the exact solution for the condensates with arbitrary spin imbalance and the fermion spectrum perturbatively in the presence of small spin imbalance. We also obtain fermion zero mode exactly without perturbation.Comment: 5 pages, 2 figures; v2 slightly improved, typos fixed, published versio

Features and heterogeneities in growing network models

Many complex networks from the World-Wide-Web to biological networks are growing taking into account the heterogeneous features of the nodes. The feature of a node might be a discrete quantity such as a classification of a URL document as personal page, thematic website, news, blog, search engine, social network, ect. or the classification of a gene in a functional module. Moreover the feature of a node can be a continuous variable such as the position of a node in the embedding space. In order to account for these properties, in this paper we provide a generalization of growing network models with preferential attachment that includes the effect of heterogeneous features of the nodes. The main effect of heterogeneity is the emergence of an "effective fitness" for each class of nodes, determining the rate at which nodes acquire new links. The degree distribution exhibits a multiscaling behaviour analogous to the the fitness model. This property is robust with respect to variations in the model, as long as links are assigned through effective preferential attachment. Beyond the degree distribution, in this paper we give a full characterization of the other relevant properties of the model. We evaluate the clustering coefficient and show that it disappears for large network size, a property shared with the Barab\'asi-Albert model. Negative degree correlations are also present in the studied class of models, along with non-trivial mixing patterns among features. We therefore conclude that both small clustering coefficients and disassortative mixing are outcomes of the preferential attachment mechanism in general growing networks.Comment: 16 pages, 6 figures, revte

Light nonabelian monopoles: Constructing dual nonabelian superconductor of more general types

In this talk we discuss a new class of N = 1 supersymmetric U(N) gauge theories, in which the low-energy magnetic effective gauge group contains multiple nonabelian factors, Pi(i) SU(r(i)), supported by light monopoles carrying associated charges. These nontrivially generalize the physics of r-vacua found in softly broken N = 2 supersymmetric QCD and yield dual nonabelian superconductor of a more general type. The matching between classical and quantum (r(1), r(2)....) vacua leads to nontrivial hints about the nonabelian duality

Ocular abnormalities in healthy Standardbred foals

Objective  To determine the prevalence and describe ocular abnormalities in healthy Standardbred foals within 48 h of birth. Animals  One hundred and two neonatal foals. Procedures  All foals had an unassisted delivery. On the basis of physical examination and the results of hematological and biochemical parameters, all foals were unaffected by systemic diseases. A complete ophthalmic examination was performed within 48 h of birth. Foals with ocular hemorrhages were re-examined weekly until the abnormalities were resolved. Results  65/102 (63.7%) foals did not show ocular abnormalities, while in 37/102 (36.3%) cases, ocular abnormalities were present. Retinal and subconjunctival hemorrhages were recorded in 19/102 (18.6%), and in 13/102 (12.7%), respectively. In 4/102 (3.9%) animals, an entropion of the lower eyelid was present. Only one foal (1%) showed a congenital nuclear unilateral cataract. No other ocular abnormalities were detected. However, all foals showed various degrees of remnants of hyaloid system. One week after the first ocular examination, retinal hemorrhages had resolved in 100% of the eyes, whereas subconjunctival hemorrhages had disappeared in all eyes by the second week following the first examination. Conclusions  The acquired ocular lesions observed with relatively high frequency in the examined healthy Standardbred foals were ocular hemorrhages, which always showed a good outcome. Although these abnormalities were present at birth, they were not considered strictly congenital but likely acquired during parturition. Instead, congenital ocular abnormalities were rarely diagnosed, and the entropion of the lower eyelid was the most common disease in the breed

Valutazione alla nascita di alcuni parametri semeiologici, ematologici e biochimici in una popolazione di 99 puledri trottatori

The aim of the present study was to evaluate some semeiotical, haematological and biochemical parameters useful to assess viability in newborn trotter foals. Materials and methods - Ninety-nine trotter foals were investigated. Each subject was examined within 5 minutes after birth, APGAR scoring was assessed, and suction reflex was evaluated. Furthermore, the interval time needed to raise the head, acquire sternal recumbency, stand and acquire colostrum were recorded. Ombelical torsion was assessed too. A blood sample was collected from the jugular vein from every newborn foal before first feed and a total CBC count, serum creatinine, serum urea, fibrinogen and glucose concentration were evaluated. At 24h after birth, IgG status was assessed (SNAP (R), IDEXX, USA). Placenta was layed out in the shape of an "F" with the allantoic surface of the allantochorion exposed. Integrity, thickness, discoloured and/or edematous areas were recorded. Amniotic fluid was also collected during delivery before the rupture of amniotic sac with a sterile 50cc syringe; amniotic fluid clearness was also assessed. Minimum and maximum values, median and standard deviation were calculated for semeiotical, haematological and biochemical data. Student t test was calculated to verify possible differences between healthy foals and foals with APGAR < 6. Statistical analysis was considered significative for p < 0.05: Results - APGAR scoring was 7-8 in 89/99; suckling reflex was present in 89/89, 85/89 foals raised the head immediately, 4/89 after 2 minutes; sternal recumbency was achieved within 1 minute in 61/89, between 1 and 2 minutes in 13/89, between 3 and 4 minutes in 3/89, between 5 and 6 minutes in 8/89 and over 6 minutes in 4/89; 24/89 foals standed within 60 minutes, 25/89 between 61 and 90 minutes, 29/89 between 91 and 120 minutes, and 11/89 after 121 minutes. 43/89 foals nursed the mare within 120 minutes, 33/89 between 121 and 180 minutes, 8/89 between 181 and 240 minutes and 5/89 after 241 minutes. IgG concentration was above 800 mg/dl in 87/89 foals and between 400 and 800 mg/dl in 2/89 subjects. APGAR scoring was < 6 in 10/99. Suckling reflex was not present in 3/10 foals; 7/10 foals raise the head immediately, 2110 within 2 minutes, 1/10 after 10 minutes; sternal recumbency was achieved within 1 minute in 4/10 foals, between 3 and 4 minutes in 2/10, between 5 and 6 minutes in 2/10 and over 6 minutes in 2110 subjects; 1/10 foals standed within 60 minutes, 3110 between 61 and 90 minutes, 6/10 subjects over 60 minutes. 3/10 foals nursed the mare within 120 minutes, 2/10 between 121 and 180 minutes, 2110 subjects between 181 and 240 minutes and 3110 over 241 minutes. Minimum and maximum values, median and standard deviation of semeiotical values are reported in Table 1. Minimum and maximum values, median and standard deviation of haematological and biochemical values, heart (HR) and respiratory rate (RR), rectal temperature are reported in Table 2. Concerning foals with APGAR 7-8, mares' placenta was thicked in 5189, edematous/discoloread areas were present in 12189, the weight was 2-8 kg (X +/- DS 5,1 +/- 1,06 kg), amniotic fluid clearness was considered optimal in 23/89, medium in 65189, scarce in 1/89. Concerning foals with APGAR < 6, mares' placenta was not thicked and/or edematous/discoloread, the weight was 2,5-7 kg (X +/- DS 4,8 +/- 1,2 kg), amniotic fluid clearness was considered optimal in 1/10, medium in 7110, scarce in 2/10. Statistical differences were significative for standing time (180vs90'), nursing the mare (200vs130) and HR (43vs60apm). Conclusions - The semeiotical data obtained in our study were similar to other surveys (Harvey et al, 1984; Bauer et al., 1984; Vaala, 1994; Madigan, 1997; Knottembelt et al., 2004), but with wider reference intervals. Haematological and biochemical values showed some differences respect to other studies (Bauer et al., 1984; Vaala, 1994; Madigan, 1997); in particular in our study we observed mild haemoconcentration and hypoglicemia. These differences could be related to the blood sampling collection time: immediately after this birth (as reported by Knottembelt, 2004) in the present study, while in most other was within 24 hours and after nursing (Harvey et al., 1984; Vaala,1994; Madigan,1997)

Determinazione alla nascita di alcuni esami di laboratorio di base in una popolazione di 99 puledri trottatori

APGAR scoring within 10’ after birth was assessed, heart rate, respiratory rate and body temperature were recorded in 11 donkey foals. The time needed to raise the head, observe suction reflex, acquire sternal recumbency, stand and acquire colostrum were recorded. Blood sample was collected before first feeding, a total CBC count, lactate and glucose concentration were evaluated. IgG status was also assessed at 24h. APGAR scoring was 7-8 and the head was raised immediately in 11/11; suckling reflex was acquired in 9,7’±4,7’, sternal recumbency within 3,7’±1,3’; standing up within 127,5’±70’; nursing the mare within 200’±67,4’. Blood lactate concentration mmol/L 2,08±0,5, blood glucose concentration mg/dl 93,7±24,5, WBC K/μL 5,9±1,5, neutrophils (N) K/μL 4,2±1,6, lymphocytes (L) K/μL 1,5±0,4, N:L 3,2±1,3. IgG was >800 mg/dl in 11/11 foals. Some of the semeiotic data, haematological and biochemical values showed some differences respect to equine foals

Bosons on a rotating ring with free boundary conditions

We consider a system of interacting non-relativistic bosons confined to a onedimensional ring in the presence of a synthetic gauge field induced by a rotating barrier. Interactions are introduced as a constraint in field space, and the barrier is modeled by general boundary conditions.Within this setup, we compute the effective action and investigate the profile of the ground state and its sensitivity from rotational velocity and the properties of the barrier