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Improving the performance of LOX/kerosene upper stage rocket engines

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Propulsion and Power Research 2017年第3期6卷 157-176页

作者： Igor n.nikischenko raymond D.Wright Roman A.Marchan Firefly Europe B.V. Blaricum 1261 GAThe Netherlands Spacefleet Ltd DevizesWiltshireSN103APUnited Kingdom

Improved liquid rocket engine cycles were proposed and analyzed via comparison with existing staged combustion and gas-generator *** key features of the proposed cycles are regenerative cooling of thrust chamber by oxygen and subsequent use of this oxygen for driving one or two oxygen *** fuel pump(s)are driven in a conventional manner,for example,using a fuel-rich gas-generator *** with staged combustion cycle based on oxygen-rich pre-burner showed that one of the proposed semi-expander cycles has a specific impulse only on 0.4%lower while providing much lower oxygen temperature,more efficient tank pressurizing system and built-in roll *** semi-expander cycle can be considered as a more reliable and cost-effective alternative of staged combustion *** semi-expander cycle can be considered as an improvement of gas-generator *** proposed semi-expander cycles were developed as a derivative of thrust chamber regenerative cooling performed by *** of existing oxygen/kerosene engines showed that replacing of kerosene regenerative cooling with oxygen allows a significant increase of achievable specific impulse,via optimization of mixture *** is especially the case for upper stage *** increasing of propellants average density can be considered as an additional benefit of mixture ratio *** was demonstrated that oxygen regenerative cooling of thrust chamber is a feasible and the most promising option for oxygen/kerosene *** of oxygen regenerative cooling and semi-expander cycles potentially allows creating the oxygen/kerosene propulsion systems with minimum specific impulse *** is important that such propulsion systems can be fully based on inherited and well-proven technical solutions.A hypothetic upper stage engine with thrust 19.6 kn was chosen as a prospective candidate for theoretical analysis of the proposed semi-expander *** newly-developed software RECS

关键词： Oxygen Kerosene Liquid rocket engine Upper stage

Selected fermented indigenous vegetables and fruits from Malaysia as potential sources of natural probiotics for improving gut health

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Food Science and Human Wellness 2023年第5期12卷 1493-1509页

作者： Olaide Olawunmi Ajibola raymond Thomas Babatunde Femi Bakare Department of Biochemistry Memorial University of NewfoundlandSt.John’sNL A1C 5S7Canada Faculty of Resource Science and Technology Universiti Malaysia SarawakKota Samarahan 94300Malaysia Institute of Biodiversity and Environmental Conservation Universiti Malaysia SarawakKota Samarahan 94300Malaysia School of Science and the Environmental Science/Boreal Ecosystem Research Initiative Memorial University of NewfoundlandCorner Brook A2H 5G4Canada Department of Biology/Biotron Experimental Climate Change Research Centre Western UniversityLondon N6A 5BCanada Environmental Pollution and Remediation Research Group Department of Chemical EngineeringMangosuthu University of TechnologyDurban 4031South Africa

In the Peninsular Malaysia and northern Borneo island of Malaysia, various rich indigenous leafy vegetables and fruits grow and contribute to the nutritional and dietary values of the population. They have high water contents, thus, naturally vulnerable to rapid food spoilage. Food preservation and processing play a vital role in the inhibition of food pathogens in fruits and vegetables that are prevalent in Malaysia. Lactic acid fermentation is generally a local-based bioprocess, among the oldest form and well-known for food-processing techniques among indigenous people there. The long shelf life of fermented vegetables and fruits improves their nutritional values and antioxidant potentials. Fermented leaves and vegetables can be utilized as a potential source of probiotics as they are host for several lactic acid bacteria such as Lactobacillus confusus, Weissella paramesenteroides, Enterococcus faecalis, Lactobacillus plantarum, Lactobacillus buchneri, Lactobacillus paracasei, Lactobacillus pentosus, Pediococcus acidilactici, Pediococcus pentosaceus and Leuconostoc mesenteroides. These strains may be more viable in metabolic systems whereby they can contribute to a substantial increase in essential biologically active element than industrial starter cultures. This review is aimed to address some essential fermented fruits and vegetables in Malaysia and their remarkable reputations as a potential sources of natural probiotics.

关键词： Ethnic Leafy vegetables Fruit Fermentation Lactic acid bacteria Malaysia

A provable-secure and practical two-party distributed signing protocol for SM2 signature algorithm

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Frontiers of Computer Science 2020年第3期14卷 203-215页

作者： Yudi ZHAnG Debiao HE Mingwu ZHAnG Kim-Kwang raymond CHOO Key Laboratory of Aerospace Information Security and Trusted Computing of Ministry of Education School of Cyber Science and EngineeringWuhan UniversityWuhan 430072China School of Computer Sciences Hubei University of TechnologyWuhan 430068China Department of Information Systems and Cyber Security and Department of Electrical and Computer Engineering University of Texas at San AntonioSan AntonioTX 78249USA

Mobile devices are widely used for data access,communications and ***,storing a private key for signature and other cryptographic usage on a single mobile device can be challenging,due to its computational ***,a number of(t,n)threshold secret sharing schemes designed to minimize private key from leakage have been proposed in the ***,existing schemes generally suffer from key reconstruction *** this paper,we propose an efficient and secure two-party distributed signing protocol for the SM2 signature *** latter has been mandated by the Chinese government for all electronic commerce *** proposed protocol separates the private key to storage on two devices and can generate a valid signature without the need to reconstruct the entire private *** prove that our protocol is secure under nonstandard ***,we implement our protocol using MIRACL Cryptographic SDK to demonstrate that the protocol can be deployed in practice to prevent key disclosure.

关键词： SM2 signature two-party signing wireless environment provable security threshold secret sharing

Control of malaria and other vector-borne protozoan diseases in the tropics: enduring challenges despite considerable progress and achievements

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Infectious Diseases of Poverty 2014年第1期3卷 1-14页

作者： Denis Zofou raymond B nyasa Dickson S nsagha Fidele ntie-Kang Henry D Meriki Jules Clement n Assob Victor Kuete Biotechnology Unit Faculty of ScienceUniversity of BueaP.O.Box 63BueaSouth West RegionCameroon Department of Public Health and Hygiene Faculty of Health SciencesUniversity of BueaBueaCameroon CEPAMOQ Faculty of ScienceUniversity of DoualaP.O.Box 8580DoualaCameroon Chemical and Bioactivity Information Centre Department of ChemistryUniversity of BueaP.O.Box 63BueaCameroon Department of Biomedical Sciences Faculty of Health SciencesUniversity of BueaBueaCameroon Department of Biochemistry University of DschangP.O.Box 67DschangCameroon

Vector-borne protozoan diseases represent a serious public health challenge,especially in the tropics where poverty together with vector-favorable climates are the aggravating *** of the various strategies currently employed to face these scourges is seriously *** enormous efforts,vaccines-which represent the ideal weapon against these parasitic diseases—are yet to be sufficiently developed and *** and vector control are therefore the sole effective attempts to minimize the disease ***,both strategies are also highly challenged by the phenomenon of drug and insecticide resistance,which affects virtually all interventions currently *** recently growing support from international organizations and governments of some endemic countries is warmly welcome,and should be optimally exploited in the various approaches to drug and insecticide research and development to overcome the burden of these prevalent diseases,especially malaria,leishmaniasis,Human African Trypanosomiasis(HAT),and Chagas disease.

关键词： Malaria Vector-borne protozoan diseases African trypanosomiasis Chagas disease Leishmaniasis Vector control Chemotherapy Vaccine development

Rorty＇s Point of Departure from Mainstream Pragmatist Approach to Epistemology

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Journal of Philosophy Study 2012年第11期2卷 845-850页

作者： raymond n. Osei Husein Inusah University of Cape Coast University of Ghana

Our main focus in this paper is to try to show Rorty＇s point of departure from mainstream pragmatist treatment of epistemology. In his pragmatic approach to epistemology, Rorty urges that a good pragmatist should abandon epistemology as a foundational and rational discipline and instead opt for conversation, the view that knowledge is an expression of judgment of a historically conditioned social group） According to Rorty, the view that we should disentangle ourselves from rigid canons of epistemology is the quest of classical pragmatism traceable to the writings of William James and John Dewey. On this showing, Rorty argues that conversationalism is consistent with mainstream or original pragmatism. Contrary to Rorty＇s claim we try to show, in the following pages, that his pragmatic approach to epistemology is a deviation from mainstream pragmatism. We establish that mainstream or classical pragmatists do not repudiate epistemology.

关键词： Rorty pragmatism epistemology conversationalism truth

Effect of particle stress tensor in simulations of dense gas-particle flows in fluidized beds

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Particuology 2018年第3期16卷 31-43页

作者： Mohammad Reza Haghgoo Donald J. Bergstrom raymond J. Spiteri Department of Mechanical Engineering University of Saskatchewan Saskatoon SK SFN 5A9 Canada Department of Computer Science University of Saskatchewan Saskatoon. SK S7N 5C9 Canada

A two-fluid model based on the kinetic theory of granular flow for the rapid-flow regime and the Coulomb friction law for the quasi-static regime is applied to predict the hydrodynamics of dense gas-particle flow in a three-dimensional fluidized bed. Two different models for the particle stress tensor that use different constitutive equations in the elastic-inertial regime are examined to assess their ability to predict bed dynamics. To understand how particle stress models affect structural features of the flow, a quantitative analysis is performed on some important aspects of the mechanics of bubbling beds that have received relatively little attention in the literature. Accordingly, different flow regimes are identified in the context of fluidized beds through the dimensionless inertial number, and the main characteristics of each regime are discussed. In addition, how the particle stress tensor manifests itself in the bubble characteristics, natural frequency of the bed, and particle Reynolds stress are investigated, all of which help to better understand the complex dynamics of the fluidized bed. The numerical results are validated against pub- lished experimental data and demonstrate the significant role of the stress tensor in the elastic-inertial regime.

关键词： Two-fluid model Inertial number Fluidized bed Flow regime Particle Reynolds stress MFIX

Strain control of layer-resolved negative capacitance in superlattices

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npj Computational Materials 2020年第1期6卷 127-130页

作者： raymond Walter Sergey Prosandeev Charles Paillard L.Bellaiche Department of Physics and Institute for nanoscience and Engineering University of ArkansasFayettevilleAR 72701USA Department of Mathematical Sciences University of ArkansasFayettevilleAR 72701USA Identity Engineering Kinesso LLCConwayAR 72032USA Institute of Physics and Physics Department of Southern Federal University Rostov-na-Donu 344090Russia Laboratoire Structures Propriétés et Modélisation des SolidesCentraleSupélecUMR CNRS 8580UniversitéParis-Saclay91190 Gif-sur-YvetteFrance

negative capacitance in BaTiO_(3)/SrTiO_(3) superlattices is investigated by Monte Carlo simulations in an atomistic effective Hamiltonian model,using fluctuation formulas for responses to the local macroscopic field that incorporates depolarizing *** show that epitaxial strain can tune the negative capacitance of the BaTiO_(3) ferroelectric layer and the overall capacitance of the *** addition,we predict and explain an original switching of the negative capacitance from the BaTiO3 layer to the SrTiO_(3) layer at low temperatures for intermediate strains.

关键词： capacitance layer resolved

First episode psychosis with extrapyramidal signs prior to antipsychotic drug treatment

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Chinese Science Bulletin 2011年第32期56卷 3361-3371页

作者： HOnER William G LAnG Donna J KOPALA Lili C MACEWAn G William SMITH Geoffrey n CHEn Eric Y H CHAn raymond C K Department of Psychiatry University of British Columbia Vancouver BC Canada Department of Radiology University of British Columbia Vancouver BC Canada Department of Psychiatry Dalhousie University Halifax NS Canada Department of Psychiatry University of Hong Kong Key Laboratory of Mental Health Institute of Psychology Chinese Academy of Sciences

Extrapyramidal movement disorders are common in chronic schizophrenia, and may be an intrinsic feature of the illness as well as related to antipsychotic drug treatment. Similar dysfunctions at illness onset may have implications for outcome, and for under- standing the mechanisms of illness. The objectives were to examine the clinical correlates of pre-treatment movement disorders at first episode of psychosis, and determine associations with neuropsychological function and striatal structure. never medicated subjects were recruited from consecutive admissions to Early Psychosis Programs with defined catchment areas in Hong Kong, China, and Halifax, Canada. Standardized clinical, neuropsychological and brain imaging assessments were carried out at baseline and following acute and long term treatment with typical or atypical antipsychotic drugs. At the Hong Kong site, we studied 84 subjects with first episode psychosis (n = 10 with EPS). At the Halifax site, we studied 40 subjects with first episode psychosis (n = 17 with EPS), and 23 healthy comparison subjects. Subjects with movement disorders prior to treatment (EPS+) had higher total PAnSS scores at baseline (mean elevation 19.9% Hong Kong, P = 0.016; 14.7% Halifax, P = 0.049). In subjects treated with atypical antipsychotics (all Halifax), EPS+ status at baseline predicted more movement disorders at long term follow up (P = 0.0005). In both cohorts, EPS+ subjects had poorer acute symptomatic treatment response assessed with the PAnSS (Hong Kong P = 0.005; Halifax P = 0.017). neuropsychological impairment related to executive dysfunction appeared greater in a small sam- ple of EPS+ subjects (Hong Kong, effect size 0.26-0.27, P n EPS+ compared with EPS-subjects (Halifax P = 0.042), and correlations between striatal volumes and age were different in the EPS+ group. In conclu- sion, pre-treatment EPS is present in a substantial minority of subjects with first episode psych

关键词：药物治疗精神病体外症状运动障碍每股收益神经功能精神分裂症

nutritional quality of formulated complementary diet from defatted almond seed,yellow maize and quality protein maize flours

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Food Production, Processing and nutrition 2020年第1期2卷 229-240页

作者： Ade raymond Adesanmi Sunday Abiodun Malomo Tayo nathaniel Fagbemi Ekiti State Primary Health Care Development Agency Ado EkitiNigeria Department of Food Science and Technology Federal University of TechnologyAkureNigeria

Traditional complementary foods are mainly starchy foods with limiting nutrient quality and can be fortified using protein rich crops like almond *** research thus aimed at investigating the nutritional quality of the formulated complementary diet from locally available almond seeds(Prunus amygdalus),high quality protein(QPM)and yellow maize after blending into *** proximate and amino acid compositions,in vitro protein qualities and functional properties of the blended flours were determined using standard *** in vivo studies involved feeding the weanling Wister albino rats with blended flours and commercial Cerelac(control),followed by hematological and histopathological determinations,while sensory attributes were evaluated by the semi-trained *** protein contents of the flour blends(24–28%)were significantly(pndispensable amino acids and improved functionalities than commercial cerelac(23%).Comparatively,the dried germinated QPM(DGQPM)has significant(pn fermented high QPM(FHQPM)(~30%),thereby indicating that the germination process improved protein quality of the ***,the in vivo data showed a positive effect of germination process as the rats fed with DGQPM has low white blood cells(30×10^(2))compared to FHQPM(42×10^(2))and cerelac(51×10^(2)).However,the fermentation process improved the packed cell volume of rats fed with FHQPM(49%)when compared to DGQPM and cerelac(47%).The formulated diets have no negative effects on the protein content(45.19–51.88 mg n/g)and weight(0.25–1.36 g)of the internal organs(liver,kidney and tissue)of the animals when compared to cerelac(53.72–55.04 mg n/g;0.25–1.98 g),*** panelists generally accepted all the formulated diets,hence encouraging their utilization in the global preparation of complimentary foods for young children to meet their nutritional needs and adding value to the locally produced underutilized alm

关键词： Quality protein Yellow maize Almond seed nutrient composition Complementary