Integrated starter alternator sizing for micro / mild hybrid vehicle using Monte Carlo simulation

The Integrated Starter Alternator (ISA) needs to cater for a very wide range of torque and speed, in both motor and generator modes and in different functionalities, such as engine starting, alternator, regenerative braking and torque boost. Furthermore, each of these functionalities, being dependent on the drive cycle, means that determining the optimal ISA torque-speed characteristics is a challenging problem. In this paper, a Monte-Carlo simulation has been reported to find the most frequently operated regions in the torque-speed plane of an ISA, using stochastic drive cycles. This has been used to determine the optimal torque-speed characteristic to inform the ISA design specification. In turn, this gives a more robust coverage of different driving patterns compared to a conventional driving cycle-based design.Commonwealth Scholarship Commissio

Nanocrystalline Powder Cores for High-Power High-Frequency Power Electronics Applications

Soft magnetic composites (SMCs) based magnetic cores are attractive in high frequency inductor design. The desired overall core permeability of SMC core can be achieved by adjusting the powder size, addition of insulation material and phosphoric acid, and pressure during the preparation process to reduce the air gap loss and ease the inductor design. The nanocrystalline alloy (Fe-Cu-Nb-Si-B) is an emerging SMC with high saturation flux density and low hysteresis loss, showing potential suitability for SMC based magnetic cores. To date, nanocrystalline alloys are mostly used in form of laminated ribbon for magnetic cores and nanocrystalline powder SMCs have been seldom used in practice. Also, neither experimental validation nor comparison with other commercialized and commonly used SMC cores has been reported. In this paper, the structure and manufacturing process of nanocrystalline powder cores are introduced. The calculation of core loss is defined for the nanocrystalline powder core. The characteristics and performance of the nanocrystalline powder toroidal core are compared with those of existing commercial SMC cores such as Fe-Si powder (X flux), Fe-Ni powder (High flux), Fe-Si-Al powder (Kool Mµ), FeNi-Mo powder (MPP). Experimental results are conducted at frequencies from 100 kHz to 600 kHz to verify the loss calculation and feasibility of this new nanocrystalline powder core

Investigation of inorganic phase change material for a semi-transparent photovoltaic (STPV) module

This is the final version. Available on open access from MDPI via the DOI in this recordThe semi-transparent photovoltaic (STPV) module is an emerging technology to harness the solar energy in the building. Nowadays, buildings are turning from energy consumers to energy producers due to the integration of the STPV module on the building envelopes and facades. In this research, the STPV module was integrated on the rooftop window of the experimental room at Kovilpatti (9°10'0" N, 77°52'0" E), Tamil Nadu, India. The performance of the STPV modules varies with respect to the geographical location, incident solar radiation, and surface temperature of the module. The surface temperature of the STPV module was regulated by the introduction of the mixture of graphene oxide and sodium sulphate decahydrate (Na2SO4.10H2O). The various concentration of the graphene oxide was mixed together with the Na2SO4.10H2O to enhance the thermal conductivity. The thermal conductivity of the mixture 0.3 concentration was found to be optimum from the analysis. The instantaneous peak temperature of the semi-transparent photovoltaic phase change material (STPV-PCM) module was reduced to 9 °C during summer compared to the reference STPV. At the same time, the energy conversion efficiency was increased by up to 9.4% compared to the conventional STPV module. Due to the incorporation of the graphene oxide and Na2SO4.10H2O, the daily output power production of the STPV module was improved by 12.16%

Socio-Demographic and Oral Health Related Risk Factors for Periodontal Disease in Inner North East London (INEL) Adults: A Secondary Analysis of the INEL Data.

Introduction: Periodontal disease is a serious collection of diseases which can lead to chronic inflammation, the destruction of tooth supporting structures and ultimately; tooth loss. It is also one of the most common diseases of the oral cavity and the major cause of tooth loss in adults and may have a major impact on the quality of life off those who suffer with the condition. Objectives: To determine the socio-demographic and oral-health-related risk factors for periodontal disease in a sample of adults living in Inner North East London (INEL), UK. Methods: A secondary analysis was conducted on data from the 2008 survey on ‘The Oral Health of Adults in INEL.’ Data were entered into the Statistical Package for Social Sciences (SPSS v19, IBM UK Ltd, Portsmouth, UK) and analysed using descriptive analysis, chi-squared tests (P ≤ 0.05), together with multivariate regression analysis. The original survey employed a multi-stage sampling procedure and the final sample size was 361. All of the participants were selected from the London Boroughs of Tower Hamlets, City and Hackney and Newham. Periodontal disease indicators, such as the loss of clinical attachment and periodontal pocket depths were cross-matched with socio-demographic and oral health-related behaviours. Associations between the two were ascertained using chi-squared statistics and multivariate regression analysis. The case-definition adopted to indicate the presence of periodontal disease was “a clinical loss of attachment and periodontal pocketing of four millimetres or more, in at-least one tooth respectively”. Results: The prevalence of periodontal disease in the original INEL sample was 39.3%. Age and gender were the variables most commonly associated with periodontal disease. The prevalence of disease demonstrated an increase with age, and in terms of gender, 48.7% of males were observed to have periodontal disease compared to 32.2% of females. Ethnicity (p=0.005) and area of residence (p=0.005) were more directly associated with periodontal pocket depth ≥ 4 mm. Dental attendance (p=0.04) and education (p=0.02) were more directly associated with clinical loss of attachment. When assessing the combined outcomes, multivariate regression analysis showed that after controlling for age and gender, subjects without a work-related qualification were more likely to have periodontal disease (OR=1.780, 95% C.I. 1.066-2.973). Dental attendance was identified as another significant predictor of periodontal disease for example subjects who never visited a dentist were at more risk than the regular attenders (OR=3.700, 95% C.I. 1.448-9.458). Conclusion: The overall prevalence of periodontal disease in an Inner North East London sample was observed to be slightly higher but generally comparable with respect to the national average, as determined by the UK Adult Dental Health Survey (1998). Of the various socio-demographic and oral-health-related risk factors analysed in the present study, age, gender, work-related qualification and dental attendance were observed to increase the likelihood of periodontal disease. Furthermore, epidemiological studies should be implemented in order to develop prevention strategies which should focus on improving access to dental services in the local community in order to reduce periodontal disease rates

Thermodynamics of a class of non-asymptotically flat black holes in Einstein-Maxwell-Dilaton theory

We analyse in detail the thermodynamics in the canonical and grand canonical ensembles of a class of non-asymptotically flat black holes of the Einstein-(anti) Maxwell-(anti) Dilaton theory in 4D with spherical symmetry. We present the first law of thermodynamics, the thermodynamic analysis of the system through the geometrothermodynamics methods, Weinhold, Ruppeiner, Liu-Lu-Luo-Shao and the most common, that made by the specific heat. The geometric methods show a curvature scalar identically zero, which is incompatible with the results of the analysis made by the non null specific heat, which shows that the system is thermodynamically interacting, does not possess extreme case nor phase transition. We also analyse the local and global stability of the thermodynamic system, and obtain a local and global stability for the normal case for 0<\gamma<1 and for other values of \gamma, an unstable system. The solution where \gamma=0 separates the class of locally and globally stable solutions from the unstable ones.Comment: 18 pages, version accepted for publication in General Relativity and Gravitatio

To evaluate the diagnostic value of protein: creatinine ratio in a single voided urine sample for quantitation of proteinuria compared to those of a 24-hour urine sample in patients with preeclampsia

Objective:&nbsp;This study was done to evaluate the diagnostic value of protein: creatinine ratio in a single voided urine sample for quantitation of proteinuria compared to those of a 24 hour urine sample in patients with preeclampsia. Methods:&nbsp;A prospective simple random sample study was done on the hypertensive pregnant women attending the antenatal clinic or admitted in Department of Obstetrics and Gynaecology. It included all women being evaluated for preeclampsia, regardless of the alerting sign or symptom, suspected severity or co-morbid conditions. The main measures were the urinary protein to urinary creatinine ratio by random (spot) direct measurement and the 24-h urinary protein excretion by a 24-h urine collection. The data obtained was statistically analyzed. Results:&nbsp;Out of the 78 patients with gestational hypertension included in our study 48 patients had significant proteinuria (e&rdquo;300mg/day). Only 2 patients had proteinuria of the range of greater than 3500mg. Among the patients, 50 had a positive protein: creatinine ratio (e&rdquo;0.3) while 28 patients had a negative protein: creatinine ratio (&lt;0.3). The P: C ratio was able to correctly identify 44 out of 48 patients with significant proteinuria (when the comparison is made with the gold-standard test; i.e., 24-hour urine protein). It could also identify 24 out of 30 patients without significant proteinuria as compared to the gold-standard test. In this study, the Protein: Creatinine ratio with a sensitivity of 91.67%, a specificity of 80%, positive predictive values 88% and the negative predictive values 85.71%. Conclusions:&nbsp;Our data suggests that the protein: creatinine ratio in single voided urine is a highly accurate test (p value &lt; 0.0000001) for discriminating between insignificant and significant proteinuria. Based on the above findings we conclude that a random urine protein excretion predicts the amount of 24- hour urine protein excretion with high accuracy. This could be a reasonable alternative to the 24-hour urine collection for detection of significant proteinuria in hospitalised pregnant women with suspected preeclampsia. Journal of College of Medical Sciences-Nepal, 2013, Vol-9, No-2, 45-53 DOI: http://dx.doi.org/10.3126/jcmsn.v9i2.9687</p

Chaos around Holographic Regge Trajectories

Using methods of Hamiltonian dynamical systems, we show analytically that a dynamical system connected to the classical spinning string solution holographically dual to the principal Regge trajectory is non-integrable. The Regge trajectories themselves form an integrable island in the total phase space of the dynamical system. Our argument applies to any gravity background dual to confining field theories and we verify it explicitly in various supergravity backgrounds: Klebanov-Strassler, Maldacena-Nunez, Witten QCD and the AdS soliton. Having established non-integrability for this general class of supergravity backgrounds, we show explicitly by direct computation of the Poincare sections and the largest Lyapunov exponent, that such strings have chaotic motion.Comment: 28 pages, 5 figures. V3: Minor changes complying to referee's suggestions. Typos correcte

Removal of ecotoxicity of 17α-ethinylestradiol using TAML/peroxide water treatment

17α -ethinylestradiol (EE2), a synthetic oestrogen in oral contraceptives, is one of many pharmaceuticals found in inland waterways worldwide as a result of human consumption and excretion into wastewater treatment systems. At low parts per trillion (ppt), EE2 induces feminisation of male fish, diminishing reproductive success and causing fish population collapse. Intended water quality standards for EE2 set a much needed global precedent. Ozone and activated carbon provide effective wastewater treatments, but their energy intensities and capital/operating costs are formidable barriers to adoption. Here we describe the technical and environmental performance of a fast- developing contender for mitigation of EE2 contamination of wastewater based upon smallmolecule, full-functional peroxidase enzyme replicas called “TAML activators”. From neutral to basic pH, TAML activators with H2O2 efficiently degrade EE2 in pure lab water, municipal effluents and EE2-spiked synthetic urine. TAML/H2O2 treatment curtails estrogenicity in vitro and substantially diminishes fish feminization in vivo. Our results provide a starting point for a future process in which tens of thousands of tonnes of wastewater could be treated per kilogram of catalyst. We suggest TAML/H2O2 is a worthy candidate for exploration as an environmentally compatible, versatile, method for removing EE2 and other pharmaceuticals from municipal wastewaters.Heinz Endowments, the Swiss National Science Foundation, the Steinbrenner Institute for a Steinbrenner Doctoral Fellowship. NMR instrumentation at CMU was partially supported by NSF (CHE-0130903 and CHE-1039870)

Holographic phase diagram of quark-gluon plasma formed in heavy-ions collisions

The phase diagram of quark gluon plasma (QGP) formed at a very early stage just after the heavy ion collision is obtained by using a holographic dual model for the heavy ion collision. In this dual model colliding ions are described by the charged shock gravitational waves. Points on the phase diagram correspond to the QGP or hadronic matter with given temperatures and chemical potentials. The phase of QGP in dual terms is related to the case when the collision of shock waves leads to formation of trapped surface. Hadronic matter and other confined states correspond to the absence of trapped surface after collision. Multiplicity of the ion collision process is estimated in the dual language as area of the trapped surface. We show that a non-zero chemical potential reduces the multiplicity. To plot the phase diagram we use two different dual models of colliding ions, the point and the wall shock waves, and find qualitative agreement of the results.Comment: 33 pages, 14 figures, typos correcte

Modern computing: Vision and challenges

Over the past six decades, the computing systems field has experienced significant transformations, profoundly impacting society with transformational developments, such as the Internet and the commodification of computing. Underpinned by technological advancements, computer systems, far from being static, have been continuously evolving and adapting to cover multifaceted societal niches. This has led to new paradigms such as cloud, fog, edge computing, and the Internet of Things (IoT), which offer fresh economic and creative opportunities. Nevertheless, this rapid change poses complex research challenges, especially in maximizing potential and enhancing functionality. As such, to maintain an economical level of performance that meets ever-tighter requirements, one must understand the drivers of new model emergence and expansion, and how contemporary challenges differ from past ones. To that end, this article investigates and assesses the factors influencing the evolution of computing systems, covering established systems and architectures as well as newer developments, such as serverless computing, quantum computing, and on-device AI on edge devices. Trends emerge when one traces technological trajectory, which includes the rapid obsolescence of frameworks due to business and technical constraints, a move towards specialized systems and models, and varying approaches to centralized and decentralized control. This comprehensive review of modern computing systems looks ahead to the future of research in the field, highlighting key challenges and emerging trends, and underscoring their importance in cost-effectively driving technological progress