Constraints on light Dark Matter fermions from relic density consideration and Tsallis statistics

The cold dark matter fermions with mass MeV scale, pair produced inside the supernova SN1987A core, can freely stream away from the supernovae and hence contributes to its energy loss rate. Similar type of DM fermions(having similar kind of coupling to the standard model photon), produced from some other sources earlier, could have contributed to the relic density of the Universe. Working in a theory with an effective dark matter-photon coupling (inversely proportional to the scale $\Lambda$) in the formalism of Tsallis statistics, we find the dark matter contribution to the relic density and obtain a upper bound on $\Lambda$ using the experimental bound on the relic density for cold non-baryonic matter i.e. $\Omega h^2 = 0.1186 \pm 0.0020$. The upper bound obtained from the relic density is shown with the lower bound obtained from the Raffelt's criterion on the emissibity rate of the supernovae SN1987A energy loss $\dot{\varepsilon}(e^+ e^- \to \chi \overline{\chi}) \le 10^{19}~\rm{erg~g^{-1}s^{-1}}$ and the optical depth criteria on the free streaming of the dark matter fermion (produced inside the supernovae core). As the deformation parameter $q$ changes from $1.0$ (undeformed scenario) to $1.1$(deformed scenario), the relic density bound on $\Lambda$ is found to vary from $\sim 4.9 \times 10^7$ TeV to $1.6 \times 10^8$ TeV for a fermion dark matter($\chi$) of mass $m_\chi = 30~\rm{MeV}$, which is almost $10$ times more than the lower bound obtained from the SN1987A energy loss rate and the optical depth criteria. \noindent {{\bf Keywords}: Dark matter, Relic density, Supernova cooling, Tsallis statistics, free-streaming, } }Comment: 18 Pages, 10 figure

Chilling Social Media: Warrantless Border Searches of Social Media Accounts Infringe Upon the Freedom of Association and the Freedom to be Anonymous Under the First Amendment

The Department of Homeland Security has instituted rules to allow Customs and Border Patrol officials to conduct a warrantless search the mobile device data, including social media accounts, of U.S. citizens entering the United States under the border search exception doctrine of the Fourth Amendment. However, U.S. Supreme Court jurisprudence has found that there are limits to government interference in the freedom of association and freedom to be anonymous. This essay analyzes such jurisprudence as it applies to the warrantless border search of social media accounts accessible from a mobile device and concludes that this warrantless search infringes the freedom of association and the freedom to be anonymous, causing a chilling effect on an individual’s participation in social network groups for the purpose of expressing political speech

Unlimited Data Search Plan: Warrantless Border Search of Mobile Device Data Likely Unconstitutional for Violating the Fundamental Right to Informational Privacy

(Excerpt) Part I of this Article discusses a case in which a United States citizen was subject to an unconstitutional warrantless border search of his mobile device data. Part II explains the history and current state of Supreme Court jurisprudence of the border search exception doctrine. Part III explains the way in which Supreme Court jurisprudence finds the right to informational privacy for mobile device data to be a fundamental right. Part IV discusses the reluctance of some legal commentators to find that a governmental intrusion on the right to informational privacy is subject to strict scrutiny. Part V finds that a warrantless border search of mobile device data is likely unconstitutional for violating the right to informational privacy under the Due Process Clause of the Fifth Amendment

Bio-based composites from bagasse using carbohydrate enriched cross-bonding mechanism: A formaldehyde-free approach

In this study, cross-bonded self-binding and bone glue-bonded particleboards were manufactured from sugarcane (Saccharum officinarum L.) bagasse with different pre-treatments of particles. Six types of panels were manufactured from bagasse particles with and without bone glue. The physical, mechanical, and thermal properties of the panels were examined according to the standards. Fourier Transform Infrared (FTIR) spectroscopy and thermogravimetric analysis (TG) were performed to investigate the changes in the chemical bonds and thermal stability of the fabricated composites, respectively. It was found that cross-bonded bagasse self-binding (TC) and bone glue-bonded (T3) panels fabricated from non-boiled bagasse particles showed higher physical and mechanical properties compared to the other types of panels. Non-boiled bagasse particles with bone glue panels showed the highest mechanical properties, i.e., modulus of rupture (MOR = 26.22 MPa), modulus of elasticity (MOE = 4302 MPa), tensile strength = 8.35 MPa, and hardness = 1.72 MPa. TC and T3 panels also showed higher thermal stability compared to the other types of panels. A new peak at 3331-3334 cm-1 for the N-H stretching vibration in the FTIR analysis represents the presence of bone glue in the cross-bonded particleboards. Thus, this research advances the production of formaldehyde-free bagasse particleboard, introducing the cross-bonding technique and sustainable bone glue

Production and characterisation of pine wood powders from a multi-blade shaft mill

Wood is an important raw material for the manufacture of consumer products and in achieving societal goals for greater sustainability. Wood powders are feedstock for many biorefining and conversion techniques, including chemical, enzymatic and thermochemical processes and for composite manufacture, 3D printing and wood pellet production. Size reduction, therefore, is a key operation in wood utilisation and powder characteristics, such as shape, particle size distribution and micromorphology play a role in powder quality and end-use application. While in a green state, the native chemical composition and structure of wood are preserved. Powders are commonly produced from wood chips using impact mills, which require pre-sized, pre-screened and pre-dried chips. These steps necessitate repeated handling, intermediate storage and contribute to dry matter losses, operation-based emissions and the degradation of the wood chemistry.This thesis investigated a new size reduction technology, known as the multi-blade shaft mill (MBSM). The MBSM performance was studied through the milling of Scots pine (Pinus sylvestris L.) wood using a designed series of experiments and through modelling with multi-linear regression (MLR) analyses. Light microscopy combined with histochemical techniques were used to investigate particle micromorphology and distribution of native extractives in powders. The aim was to evaluate the technical performance of the MBSM with relation to operational parameters, to characterise the produced powders and to evaluate the technology through comparison with impact milling.The results showed that the MBSM could effectively mill both green and dry wood. Produced powders showed distinct differences compared to those obtained using a hammer mill (HM). The specific milling energy of the MBSM was lowest for green wood and within the range of other established size reduction technologies. However, much narrower particle size distributions were observed in MBSM powders and they had significantly greater amounts of finer particles. Particles with high aspect ratio and sphericity were a characteristic of MBSM powders and this Production and characterisation of pine wood powders from a multi-blade shaft mill was true for wood milled above and below its fibre saturation point. MBSM powders from green wood showed evidence of higher specific surface area, larger pore volume and greater micropore diameter than those from HM powder. Preliminary microscopic examination suggested that cell walls in MBSM powders showed evidence of retaining their original native wood structure. Consequently, their extractive content appeared intact. This was in contrast to HM powder and it may reflect the differences between the two size reduction mechanisms. According to the produced MLR models, the results suggest that MBSM milling is more akin to a sawing process and opposite to that of impact-based mills