933 research outputs found
Counting Steps: A Finitist Approach to Objective Probability in Physics
We propose a new interpretation of objective probability in statistical physics based on physical computational complexity. This notion applies to a single physical system (be it an experimental set-up in the lab, or a subsystem of the universe), and quantifies (1) the difficulty to realize a physical state given another, (2) the 'distance' (in terms of physical resources) between a physical state and another, and (3) the size of the set of time-complexity functions that are compatible with the physical resources required to reach a physical state from another. This view (a) exorcises 'ignorance' from statistical physics, and (b) underlies a new interpretation to non-relativistic quantum mechanics
Britain, her Middle East mandates and the emergence of Saudi-Arabia, 1926-1932: a study in the process of British policy-making and in the conduct and development of Britain's relations with Ibn Saud
The aim of this study is to analyse Britain's relations with Ibn Saud between 1926 when he conquered the Hejaz and 1932, when reconciliation between the Saudis and the Hashemites was achieved. From analysis of the policy making process it is hoped to establish the causes of Britain's involvement in Arabian. affairs and the part which Britain played in the creation of Saudi Arabia.
My thesis is, divided into six chapters. Chapter I covers early attempts made by Britain and Ibn Saud towards the establishment of a close relationship, and examines the reasons which retarded these endeavours until 1925. Three main stages can be noted in Anglo-Saudi relations during the period under review:
1- January 1926 to May 1927. During this stage Ibn Saud was busily engaged in establishing his authority in the Hejaz seeking for this purpose support from Britain, from other Great Powers and throughout the Muslim World. Chapter 2 investigates the attitudes of the British Government and of the British Muslims, particularly the Indians, towards the Saudi conquest of the Hejaz. Chapter 3 analyses the making of the treaty of Jeddah (1927) throwing new light on British interests in Arabia and the means of protecting them. It also explores the British decision-making process.
2- June 1927 to-, December 1930. With Anglo-Saudi relations now established on an equal footing, fresh troubles, in November 1927, arose on the border areas with the Mandates and immediately threatened all the agreements reached. Chapter 4 analyses the ensuing crisis and the unresolved dilemma posed by the Ikhwan and the frontier posts question. Chapter 5 examines the hitherto unexplored area of contacts and deliberations-which led to Anglo-Saudi collaboration in suppressing the Ikhwan rebellion.
3- January 1930 to-December 1932. The opportunity was now more favourable for Britain to promote reconciliation between the Saudis and the Hashemites. Chapter 6 is entirely devoted to this successful achievement
Accuracy and Air Temperature Dependency of Commercial Low-cost NDIR CO<sub>2 </sub>Sensors: An Experimental Investigation
Detection of cytosolic bacteria by inflammatory caspases
The sanctity of the cytosolic compartment is rigorously maintained by a number of innate immune mechanisms. Inflammasomes detect signatures of microbial infection and trigger caspase-1 or caspase-11 activation, culminating in cytokine secretion and obliteration of the replicative niche via pyroptosis. Recent studies have examined inflammatory caspase responses to cytosolic bacteria, including Burkholderia, Shigella, Listeria, Francisella, and Mycobacterium species. For example, caspase-11 responds to LPS introduced into the cytosol after Gram-negative bacteria escape the vacuole. Not surprisingly, bacteria antagonize these responses; for example, Shigella delivers OspC3 to inhibit caspase-4. These findings underscore bacterial coevolution with the innate immune system, which has resulted in few, but highly specialized cytosolic pathogens
Explaining the unobserved: why quantum mechanics is not only about information
A remarkable theorem by Clifton, Bub and Halvorson (2003)(CBH) characterizes
quantum theory in terms of information--theoretic principles. According to Bub
(2004, 2005) the philosophical significance of the theorem is that quantum
theory should be regarded as a ``principle'' theory about (quantum) information
rather than a ``constructive'' theory about the dynamics of quantum systems.
Here we criticize Bub's principle approach arguing that if the mathematical
formalism of quantum mechanics remains intact then there is no escape route
from solving the measurement problem by constructive theories. We further
propose a (Wigner--type) thought experiment that we argue demonstrates that
quantum mechanics on the information--theoretic approach is incomplete.Comment: 34 Page
Numerical Investigation of Combustion in HCCI Diesel Engine Fuelled with Biodiesel Blends
Homogeneous Charge Compression Ignition (HCCI) is an advanced combustion technology being considered for internal combustion engines due to the potential for high fuel conversion efficiency and extremely low particulate matter (PM) and Nitrogen Oxides (NOx) emissions. In HCCI engines, there is no direct control method for auto ignition time. A common method to indirectly control the ignition timing in HCCI combustion engines is altering engineâs parameters which can affect the combustion. Previous research has indicated that fuel chemistry has a strong impact on HCCI combustion. This work introduces a new predictive multi-zone model for the description of combustion in HCCI engines. A multi zone model with reduced fuel chemistry was developed to simulate the combustion process in HCCI engines and predict engine performance. In this work, a parametric study on Diesel/Biodiesel blends(D80B20) HCCI combustion is conducted in order to identify the effect of equivalence ratio values (0.1786, 0.27, 0.37, and 0.4762) on combustion and engine performance parameters. Two kinds of parameters will be discussed. First, in-cylinder pressure, temperature and net heat release rate diagrams at altering Diesel/Biodiesel dose (0%, 20%, 40%, 60%), then the second category, the variation of start of combustion and combustion duration which are performance parameters of HCCI Diesel Engine
Thrombocytopenia in systemic lupus erythematosus patients and its association with antiphospholipid antibodies
Introduction: Systemic lupus erythematosus (SLE) is a complex systemic autoimmune disease, characterized by immune-mediated inflammation in different organs. The course of the disease is characterized by relapses and remissions, and the degree of severity of the clinical manifestations is greatly affected by the number and nature of the various organ affection. The death rate in patients with SLE is still significant, and it may be due to lupus activity, when vital organs are affected, the complications of treatment especially infections or long-term complications, such as cardiovascular disorders. Objective: To detect the relation between thrombocytopenia in SLE patients and presence antiphospholipid antibodies.Patients and methods: This study was a cross-sectional study included 100 SLE patients who attended to Sohag University Hospitals. Patients included in this study were classified as SLE patients according to either the 2012 SLICC criteria or the new 2017 ACR/EULAR SLE classification criteria. All of the participants were subjected to the following: Full history, full clinical examination, routine investigations, ANA by immunofluorescence, and ANA profile for the most common 19 autoantibodies by immunoblot. All of the participants were subjected to detection of serum titers of all antiphospholipid antibodies (aPLs) including lupus anticoagulant (LA), anti-cardiolipin (aCL) and anti-beta2-glycoprotein I (ab2GPI).Results: In this study, we demonstrated that aPLs are strongly associated with increased risk of thrombocytopenia in SLE patients. We identified aPL profiles, especially LA and IgM isotypes, as biomarkers for the risk stratification of thrombocytopenia in SLE patients.Conclusions: We concluded that aPLs are strongly associated with increased risk of thrombocytopenia in SLE patients
A Critical Review of the Performance, Combustion, and Emissions âCharacteristics of PCCI Engine Controlled by Injection Strategy and âFuel Properties
As internal combustion engines (ICEs) produce serious emissions and a big part of greenhouse gases from fuel combustion. Due to the universal concerns about degradation in the ambient environment, limitations on exhaust emissions, depletion of petroleum reserves, and global warming, many strict regulations have been launched on the standard emissions released from engines. Premixed charge compression ignition (PCCI) is a promising technique to overcome these challenges in recent years which can simultaneously reduce NOx and soot emissions and substantially improve thermal efficiency. The PCCI combustion concept has the advantages of both SI and CI engines, like SI engines as the charge is premixed which produces low emissions and like CI engines the fuel-air mixture is auto-ignited as a result of compression which leads o high thermal efficiency. Normally, PCCI combustion is a single-stage combustion process achieved by employing early injection timing to increase the time available for mixing fuel and air by using single-fuel and split fuel (pilot/main) injection tactics, in which a large fraction of fuel burns in premixed combustion phase resulting in relatively lower in-cylinder temperatures compared to compression ignition (CI) combustion. Thus, the objective of this paper is to provide an inclusive review of the effects of fuel injection timings, ratios, pressure, and fuel properties on the PCCI engine combustion performance improvement and emission reduction, this review has been analyzed extensively based on the published studies to provide and discuss different strategies for the control of PCCI technique of combustion at wide range of speed and load
Experimental Investigation on Spray Characteristics of Waste Cooking Oil Biodiesel/Diesel Blends at Different Injection Parameters
Biodiesel is a promising alternative solution for the energy crisis, as it is renewable, biodegradable, non - toxic and it has a fully competitive edge with petrol diesel in most technical aspects. Because of the increasing global request for diesel fuel consumption, consumption of non-renewable fossil fuels, exhaust emissions, all these led to search about alternative fuels. Biodiesel is one of the potential alternatives for depleting fossil fuels. Biodiesel fuel is an eco-friendly and renewable source of energy. Biodiesel fuel is an eco-friendly and renewable source of energy. Biodiesel is one of the best solutions and alternatives available to all countries of the world. Inedible plants and vegetable oils such as Jatropha oil, Karanji Pongamia oil, Neem oil, Jojoba oil, Cottonseed oil, Linseed oil, Mahua oil, Deccan hemp oil, Kusum oil, Orange oil, and Rubber seed oil were used as biodiesel in diesel engine. Biodiesel is produced by chemical methods from vegetable oils, but the use of vegetable oils is a high cost.Scientists searched for other sources and at the same time has a low cost. They found that waste cooking oil is the ideal solution to that problem. Four methods to minimize the high viscosity of vegetable oils to enable their use in common diesel engines without operational problems such as engine charges have been investigated: blending with petro diesel, pyrolysis, microemulsification (solvent blending), and transesterification. Transesterification is by far the most common method. Only the transesterification reaction leads to the products commonly known as biodiesel, i.e., alkyl esters of oils and fats. Biodiesel was produced from waste Cooking-oil by transesterification process have been applied for most countries to improve and raise the national energy return. Blends of WCOB and diesel were used instead of pure diesel fuel in diesel engine. However, the spray characteristic of the injected fuel depends on different parameters such as fuel injection pressure, the temperature of the injected fuel, ambient pressure, fuel viscosity, and fuel density.In internal combustion engines, such as the diesel engine used to conduct the experiment, a 20 mm window and a transparent glass box are used to facilitate the visualization of spray characteristics. The spray characteristics of the diesel/ waste cooking oil biodiesel blends fuel were studied experimentally at different injection pressure and temperature. Spray characteristics of biodiesel WCOB / diesel under various injection pressures of 150 to 300 bar and injection temperature of 25 to 275 ÂșC have been measured and illustrated by sparing the fuel blends in a surrounding area using a high-speed Digital camera. In this work, the biodiesel/diesel blend of B40D60 has been tested. The experimental data shows the WCOB biodiesel of B40D60 gives longer spray tip penetration and spray angle are smaller than those of diesel fuels at different pressure and temperature
The Measurement Problem and two Dogmas about Quantum Mechanics
According to a nowadays widely discussed analysis by Itamar Pitowsky, the theoretical problems of QT are originated from two âdogmasâ: the first forbidding the use of the notion of measurement in the fundamental axioms of the theory; the second imposing an interpretation of the quantum state as representing a systemâs objectively possessed properties and evolution. In this paper I argue that, contrarily to Pitowsky analysis, depriving the quantum state of its ontological commitment is not sufficient to solve the conceptual issues that affect the foundations of QT.
In order to test Pitowskyâs analysis I make use of an argument elaborated by Amit Hagar and Meir Hemmo, showing how some probabilistic interpretations of QT fail at dictating coherent predictions in Wignerâs Friend situations. More specifically, I evaluate three different probabilistic approaches: qBism, as a representative of the epistemic subjective interpretation of the quantum state; Jeff Bubâs information-theoretic interpretation of QT, as an example of the ontic approach to the quantum state; Itamar Pitowskyâs probabilistic interpretation, as an epistemic but objective interpretation. I argue that qBism succeeds in providing a formal solution to the problem that does not lead to a self-contradictory picture, although the resulting interpretation leads to an interpretation where the real subject matter of QT clashes alarmingly with scientific practice. The other two approaches, instead, strictly fail in Wignerâs Friend scenarios, showing in such a way that they donât provide a genuine solution to the problem
- âŠ