2,519 research outputs found
Multi-parameter approach to R-parity violating SUSY couplings
We introduce and implement a new, extended approach to placing bounds on
trilinear R-parity violating couplings. We focus on a limited set of leptonic
and semi-leptonic processes involving neutrinos, combining multidimensional
plotting and cross-checking constraints from different experiments. This allows
us to explore new regions of parameter space and to relax a number of bounds
given in the literature. We look for qualitatively different results compared
to those obtained previously using the assumption that a single coupling
dominates the R-parity violating contributions to a process (SCD). By combining
results from several experiments, we identify regions in parameter space where
two or more parameters approach their maximally allowed values. In the same
vein, we show a circumstance where consistency between independent bounds on
the same combinations of trilinear coupling parameters implies mass constraints
among slepton or squark masses. Though our new bounds are in most cases weaker
than the SCD bounds, the largest deviations we find on individual parameters
are factors of two, thus indicating that a conservative, order of magnitude
bound on an individual coupling is reliably estimated by making the SCD
assumption.Comment: 30 pages, 8 figures, 2 tables. Typos fixed, two references added and
references updated. Eq. (41) removed, Eq. (40) and text modified. Published
versio
Seeing the halo rotation of nearby spiral galaxies using Planck data
The rotation of the galactic halos is a fascinating topic which is still waiting to be addressed. Planck data have shown the existence of a temperature asymmetry towards the halo of several nearby galaxies, such as M31, NGC 5128, M33, M81 and M82. However, the cause of this asymmetry is an open problem. A possibility to explain the observed effect relies on the presence of “cold gas clouds” populating the galactic halos, which may be the answer to the so-called missing baryon problem. Here, we present a technique to estimate an upper limit to the rotational velocity of the halo of some nearby spiral galaxies using both their dynamical masses and the Planck data
Robust moving horizon state estimation for uncertain linear systems using linear matrix inequalities
This paper investigates the problem of state estimation for linear-time-invariant (LTI) discrete-time systems subject to structured feedback uncertainty and bounded disturbances. The proposed Robust Moving Horizon Estimation (RMHE) scheme computes at each sample time tight bounds on the uncertain states by solving a linear matrix inequality (LMI) optimization problem based on the available noisy input and output data. In comparison with conventional approaches that use offline calculation for the estimation, the suggested scheme achieves an acceptable level of performance with reduced conservativeness, while the online computational time is maintained relatively low. The effectiveness of the proposed estimation method is assessed via a numerical example
Lepton Polarization Asymmetry in B l l(bar) decays in R-parity violating Minimal Supersymmetric Standard Model
We study the implication of R-parity violating Rp Minimal Supersymmetric
Standard Model (MSSM) model in lepton polarization asymmetry ALP in B l l(bar)
decays . The analysis show that the ALP is significant in a certain
phenomenological parametric region of Yukawa couplings. We have also placed
indirect bounds on Lambda' lambda couplings as obtained from B t t(bar).Comment: 6 pages, 4 figures Changes of notation in Eq(8-11,17-19),Eq.20 adde
Investigating processing window of Affinisol™ and Plasdone™ - S630 polymers during hot-melt extrusion (for 3D printing by fused deposition modelling)
There are numerous polymers that have been used commercially to produce pharmaceutical solid dispersions and solutions from hot melt extrusion. Affinisol™ (HPMC) and Plasdone™ S630 (PVP based co-povidone copolymer) have been used in the present work to determine the viable processing space with regards thermal and work input on a twin screw extruder. Processing viability has been determined by monitoring degradation, initially assessed by physical appearance and colour of the extrudates across the full operating range of a twin screw extruder. It has been found that the Affinisol™ had a relatively narrow viable operating window compared with the Plasdone™
Assessment of Obesity, Dyslipidemia, Hyperglycemia, and Pro-Inflammatory Cytokines as Cardiovascular Disease Risk Factors in Acromegaly Patients
تعد أمراض القلب والأوعية الدموية واحدة من أكثر الأمراض المصاحبة المرتبطة بتضخم الأطراف انتشارًا ، وتحدث في 60 بالمائة من مرضى ضخامة الأطراف. يهدف البحث الى تقييم العلاقة بين هرمون النمو والأنسولين شبيه عامل النمو -1 مع السمنة ,اضطراب الدهون ,ارتفاع السكر في الدم والسيتوكينات المؤيدة للالتهابات (IL-2, IL-6, IL-10)كعامل خطر لاضطراب القلب والأوعية الدموية لدى مرضى ضخامة النهايات . اشتملت الدراسة على 80 شخصًا تم تقسيمهم إلى قسمين: 40 مريضًا من ضخامة النهايات و 40 شخصا سليما كمجموعة تحكم. أشارت النتائج إلى زيادة الوزن ، وارتفاع السكر في الدم ، وارتفاع ضغط الدم ، واضطراب الدهون ، وارتفاع مستويات الإنترلوكينات (2، 6، و 10) ، وأظهرت نتائج الارتباط ارتباطًا إيجابيًا معنويًا لكل من GH و IGF-1 مع كل من الوزن ، مؤشر كتلة الجسم ، ضغط الدم الانقباضي ، ضغط الدم الانبساطي ، FBS ، HbA1c ، الكوليسترول ، الدهون الثلاثية ، LDL ، IL6 ، IL2 ، ومؤشر تصلب الشرايين ، بينما يظهر فقط IGF-1 ارتباطًا معنويًا بـ. IL10. نستنتج أن المستويات المرتفعة من IL2 و IL6 و IL 10 وارتباطها مع كل من GH و IGF-1 بالإضافة إلى اضطراب الدهون وارتفاع السكر في الدم ومعايير ارتفاع ضغط الدم لمرضى ضخامة النهايات تقترح ضرورة المسح السريري لاضطراب القلب والأوعية الدموية لمرضى ضخامة الاطراف.Cardiovascular disease is one of the most common comorbidities associated with enlarged extremities, occurring in 60 % of patients with acromegaly. The aim of this study is to evaluate the relationship of growth hormone and insulin such as growth factor-1 with obesity, dyslipidemia, hyperglycemia, and pro-inflammatory cytokines (IL-2, IL-6, IL-10), as risk factors for cardiovascular disorder in acromegaly patients. Eighty subjects were included and categorized into two groups: 40 acromegaly patients and 40 of the control group. The results indicated weight excess, hyperglycemia, hypertension, lipid disorder, and elevated levels of interleukins (2, 6, and 10). The correlation of both GH and IGF-1 with each of weight, BMI, systolic blood pressure, diastolic blood pressure, FBS, HbA1c, cholesterol, triglyceride, LDL, IL6, IL2, and the atherogenic index was found to be positive and significant. Meanwhile, only IGF-1 was significantly correlated with IL10. We conclude that elevated levels of IL2, IL6, IL 10 and their association with both GH and IGF-1 as well as to lipid disorder, hyperglycemia, and hypertension criteria of acromegaly patients are all risk factors for cardiovascular disease, suggesting the necessary clinical examination for cardiovascular disorder in patients with acromegaly patients
Chiral Plaquette Polaron Theory of Cuprate Superconductivity
Ab-initio density functional calculations on explicitly doped
La(2-x)Sr(x)CuO4 find doping creates localized holes in out-of-plane orbitals.
A model for superconductivity is developed based on the assumption that doping
leads to the formation of holes on a four-site Cu plaquette composed of the
out-of-plane A1 orbitals apical O pz, planar Cu dz2, and planar O psigma. This
is in contrast to the assumption of hole doping into planar Cu dx2-y2 and O
psigma orbitals as in the t-J model. Interaction of holes with the d9 spin
background leads to chiral polarons with either a clockwise or anti-clockwise
charge current. When the polaron plaquettes percolate through the crystal at
x~0.05 for LaSrCuO, a Cu dx2-y2 and planar O psigma band is formed. Spin
exchange Coulomb repulsion with chiral polarons leads to D-wave
superconductivity. The equivalent of the Debye energy in phonon
superconductivity is the maximum energy separation between a chiral polaron and
its time-reversed partner. An additive skew-scattering contribution to the Hall
effect is induced by chiral polarons and leads to a temperature dependent Hall
effect that fits the measured values for LaSrCuO. The integrated imaginary
susceptibility satisfies omega/T scaling due to chirality and spin-flip
scattering of polarons along with a uniform distribution of polaron energy
splittings. The derived functional form is compatible with experiments. The
static spin structure factor is computed and is incommensurate with a
separation distance from (pi,pi) given by ~(2pi)x. Coulomb scattering of the
x2-y2 band with polarons leads to linear resistivity. Coupling of the x2-y2
band to the undoped Cu d9 spins leads to the ARPES pseudogap and its doping and
temperature dependence.Comment: 32 pages, 17 figure
Simulations of the full impact of the 40 TeV FCC proton beam with solid copper cylindrical target and the problem of hydrodynamic tunneling
Chandra Reveals Heavy Obscuration and Circumnuclear Star Formation in Seyfert 2 Galaxy NGC 4968
We present the Chandra imaging and spectral analysis of NGC 4968, a nearby (z
= 0.00986) Seyfert 2 galaxy. We discover extended (1 kpc) X-ray emission
in the soft band (0.5 - 2 keV) that is neither coincident with the narrow line
region nor the extended radio emission. Based on spectral modeling, it is
linked to on-going star formation (2.6-4 M_{\sun} yr). The soft
emission at circumnuclear scales (inner 400 pc) originates from hot gas,
with kT 0.7 keV, while the most extended thermal emission is cooler (kT
0.3 keV). We refine previous measurements of the extreme Fe K
equivalent width in this source (EW = 2.5 keV), which suggests
the central engine is completely embedded within Compton-thick levels of
obscuration. Using physically motivated models fit to the Chandra spectrum, we
derive a Compton-thick column density (
cm) and an intrinsic hard (2-10 keV) X-ray luminosity of
3-8 erg s (depending on the presumed geometry of
the obscurer), which is over two orders of magnitude larger than that observed.
The large Fe K EW suggests a spherical covering geometry, which could
be confirmed with X-ray measurements above 10 keV. NGC 4968 is similar to other
active galaxies that exhibit extreme Fe K EWs (i.e., 2 keV) in that
they also contain ongoing star formation. This work supports the idea that gas
associated with nuclear star formation may increase the covering factor of the
enshrouding gas and play a role in obscuring AGN.Comment: 11 pages, 8 figures, 4 tables. Accepted for publication in Ap
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Privacy-preserving COVID-19 Contact Tracing Blockchain
The outbreak of the COVID-19 virus has caused widespread panic and global initiatives are geared towards treatment and limiting its spread. With technological advancements, several mechanisms and mobile applications have been developed that attempt to trace the physical contact made by a person with someone who has been tested COVID-19 positive. While designing these apps, user's privacy has been an afterthought and has resulted in mass violations of privacy of the public and the patients. A total of 32 countries have designed apps and rely on them as a strategy to flatten the pandemic curve. Along with lack of privacy, these methodologies are centralized, where they are fully controlled by the government and the healthcare providers. Owing to these and many other concerns, people are hesitant in the adoption of these technologies. This paper presents a detailed analysis of user tracking apps belonging to 32 countries, thus demonstrating that they collect personal data and are a gross violation of user privacy. This paper presents a novel architecture for the efficient, effective and privacy-preserving contact tracing of COVID-19 patients using blockchain. The proposed architecture preserves the privacy of individuals and their contact history by encrypting all the data specific to an individual using a privacy-preserving Homomorphic encryption scheme and storing it on a permissioned blockchain network. The contacts made with a COVID-19 positive patient are identified by performing search queries directly over the Homomorphic encrypted data stored in the blocks. Therefore, only those contacts that are suspected to be COVID-19 positive may be decrypted by the healthcare professional or government for further contact tracing/diagnosis and COVID-19 testing; thereby leading to enhanced privacy
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